a few network problems - Networking

This is a discussion on a few network problems - Networking ; Hi, I’m having a few network problems that I would appreciate some pointers on solutions. I have a server running debian linux, which has been working for a few months now. But I have recently encountered a few problems. The ...

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  1. a few network problems

    Hi,

    I’m having a few network problems that I would appreciate some pointers
    on solutions.

    I have a server running debian linux, which has been working for a few
    months now. But I have recently encountered a few problems. The server
    is connected to the internet via an ADSL modem and gets its IP via DHCP
    from my ISP. Connected to it on the internal network are two PC running
    windows XP and a due boot laptop running Linux / windows XP.

    The problems I am having are:

    1. Losing IP number. When I boot up I get an IP number from my ISP with
    a time out of 400 – 600 seconds. My connection to the internet lasts for
    about 5 minutes then I lose the connection. When I run ifconfig I see I
    have lost my IP address provided by my ISP and have an address have an
    address starting with 169. This problem started on Saturday evening but
    cleared up itself on Sunday morning. Things were working fine again
    until Wednesday evening when the problem reoccurred. This made me think
    it was a problem with my ISP but they didn’t seam to have a clue what
    the problem could be. So I check if the windows machine running XP can
    connect and it can. No problems in windows. What I would like to know
    is; is this a problem with my server or my ISP Why does it work under
    windows but not linux? If the problem is with my sever, how do I find
    out what the problem is and fix it?

    2. This is related to the first problem. When I lose connection to my
    ISP I also lose connection to all computers on the internal network. I
    get “network unreachable” errors even with the server. I thought this
    might be a DNS problem as I’m using my ISP’s DNS. However, after
    setting up DNS on my server and using that the problem remains. Any
    ideas what could cause it and how to fix it?

    3. This problem is an old problem that I have had since first setting up
    the server. I have set up samba to allow directory sharing across the
    network. I can access shared directories on the windows machine from
    linux with no problems. I can access shared directories on a linux
    machine from a windows machine. However, I can not access shared
    directories on windows machines from a windows machine. Also, sometimes
    I can see the other machines on the network from a windows machine and
    sometimes I can’t. On one occasion I could see all the other computers
    on the network from a windows machine and as I was looking all the other
    computer vanished! As things work from the linux end, am I correct in
    assuming the problem is with windows? If so, how do I go about fixing it?

    Thanks for your time.

  2. Re: a few network problems

    AAW wrote:
    > Hi,
    >
    > I’m having a few network problems that I would appreciate some pointers
    > on solutions.
    >
    > I have a server running debian linux, which has been working for a few
    > months now. But I have recently encountered a few problems. The server
    > is connected to the internet via an ADSL modem and gets its IP via DHCP
    > from my ISP. Connected to it on the internal network are two PC running
    > windows XP and a due boot laptop running Linux / windows XP.
    >
    > The problems I am having are:
    >
    > 1. Losing IP number. When I boot up I get an IP number from my ISP
    > with a time out of 400 – 600 seconds. My connection to the internet
    > lasts for about 5 minutes then I lose the connection. When I run
    > ifconfig I see I have lost my IP address provided by my ISP and have an
    > address have an address starting with 169. This problem started on
    > Saturday evening but cleared up itself on Sunday morning. Things were
    > working fine again until Wednesday evening when the problem reoccurred.
    > This made me think it was a problem with my ISP but they didn’t seam to
    > have a clue what the problem could be. So I check if the windows machine
    > running XP can connect and it can. No problems in windows. What I would
    > like to know is; is this a problem with my server or my ISP Why does it
    > work under windows but not linux? If the problem is with my sever, how
    > do I find out what the problem is and fix it?
    >

    My first resort would be to do a reinstall of the dhcp client software.
    Also, There will be log messages somewhere in /var/log/ (daemon.log on
    my firewall) giving details of the link state and any negotiation messages.
    > 2. This is related to the first problem. When I lose connection to my
    > ISP I also lose connection to all computers on the internal network. I
    > get “network unreachable” errors even with the server. I thought this
    > might be a DNS problem as I’m using my ISP’s DNS. However, after
    > setting up DNS on my server and using that the problem remains. Any
    > ideas what could cause it and how to fix it?
    >

    This part should be independent of 1 unless the dhcp client is upsetting
    things. First call would be the output of ifconfig and route -n under
    both conditions (with and without the IP), I'd also check
    /etc/network/interfaces
    /etc/[network|ppp]/ip-[down|up].d/
    and any scripts associated with your modem driver.

    --
    Keith Blow

  3. Re: a few network problems

    Keith,

    Thanks. Sounds like a good start. I will have a go when I get back home.


  4. Re: a few network problems

    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA1


    >
    > 3. This problem is an old problem that I have had since first setting
    > up the server. I have set up samba to allow directory sharing across the
    > network. I can access shared directories on the windows machine from
    > linux with no problems. I can access shared directories on a linux
    > machine from a windows machine. However, I can not access shared
    > directories on windows machines from a windows machine. Also, sometimes
    > I can see the other machines on the network from a windows machine and
    > sometimes I can’t. On one occasion I could see all the other computers
    > on the network from a windows machine and as I was looking all the other
    > computer vanished! As things work from the linux end, am I correct in
    > assuming the problem is with windows? If so, how do I go about fixing it?
    >

    Hello Andrew:
    first of all you shlould think that the user from one windows machine
    must exist on the other machine, both users must have the same
    passwords, otherwise you will experience a strange beahvior on this.

    as a next step you should test the following: ping one machine to the
    tother. is it working?
    then i would test the wins/dns resolution:

    take the computername from the other machine and make:
    ping workstation1 (f.i.) this should work on any windows network. if
    this is not working you can call the computer by name or ip from the
    point run in the windows panel with:
    \\workstation1
    \\ip-address
    in both cases you should see an exact errormessage. if the
    networkneighboorhodd is not working or not browseable so you can access
    the shared folders in most cases.
    for further investigations you should have a look in the loggings from
    the samba server, sometimes there are interesting loggings to find.
    /var/log/samba/smbd.conf

    Greetings Randolf Balasus







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    Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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    na6J2KuHZLHOez0lXFYlGFY=
    =Lhm2
    -----END PGP SIGNATURE-----

  5. Re: a few network problems

    Randolf,


    <
    > must exist on the other machine, both users must have the same
    > passwords, otherwise you will experience a strange beahvior on this.>>

    Yes, the user exists and I can ping the other machines.

    <>

    That bit I haven't check so will do.

    Thanks.


    Randolf Balasus wrote:
    > -----BEGIN PGP SIGNED MESSAGE-----
    > Hash: SHA1
    >
    >
    >> 3. This problem is an old problem that I have had since first setting
    >> up the server. I have set up samba to allow directory sharing across the
    >> network. I can access shared directories on the windows machine from
    >> linux with no problems. I can access shared directories on a linux
    >> machine from a windows machine. However, I can not access shared
    >> directories on windows machines from a windows machine. Also, sometimes
    >> I can see the other machines on the network from a windows machine and
    >> sometimes I can’t. On one occasion I could see all the other computers
    >> on the network from a windows machine and as I was looking all the other
    >> computer vanished! As things work from the linux end, am I correct in
    >> assuming the problem is with windows? If so, how do I go about fixing it?
    >>

    > Hello Andrew:
    > first of all you shlould think that the user from one windows machine
    > must exist on the other machine, both users must have the same
    > passwords, otherwise you will experience a strange beahvior on this.
    >
    > as a next step you should test the following: ping one machine to the
    > tother. is it working?
    > then i would test the wins/dns resolution:
    >
    > take the computername from the other machine and make:
    > ping workstation1 (f.i.) this should work on any windows network. if
    > this is not working you can call the computer by name or ip from the
    > point run in the windows panel with:
    > \\workstation1
    > \\ip-address
    > in both cases you should see an exact errormessage. if the
    > networkneighboorhodd is not working or not browseable so you can access
    > the shared folders in most cases.
    > for further investigations you should have a look in the loggings from
    > the samba server, sometimes there are interesting loggings to find.
    > /var/log/samba/smbd.conf
    >
    > Greetings Randolf Balasus
    >
    >
    >
    >
    >
    >
    >
    > -----BEGIN PGP SIGNATURE-----
    > Version: GnuPG v1.4.6 (GNU/Linux)
    > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
    >
    > iD8DBQFHPCfkPtLQAXC/xvYRAuwXAJ9RlhUHqGnNYmk5RB+vrtmvTavKoQCfY8Ts
    > na6J2KuHZLHOez0lXFYlGFY=
    > =Lhm2
    > -----END PGP SIGNATURE-----


  6. Re: a few network problems

    I did an uninstall and a reinstall but no change. So I have had a look
    at the logs. I can see that it gets its IP address from my ISP :

    Nov 15 15:46:04 skamis dhclient: bound to 213.66.199.118 -- renewal in
    530 seconds.

    and then I can see that it loses its address :

    Nov 15 15:46:44 skamis dhclient: DHCPRELEASE on eth0 to 213.66.199.1 port 67

    ....

    Iautoip: Sending probe #0 for IP address 169.254.81.0.


    but I don't really follow why. One thing I note in the log is the bit
    about "Avahi detected that your currently configured local DNS server
    serves a domain .local" leading to "Avahi disabled itself". Could this
    be the source of the problem?

    Part of the log is bellow. Does it help to work out why I lose my IP
    address?

    Thanks for your time.

    log -----

    Nov 15 15:45:50 skamis dhclient: Internet Systems Consortium DHCP Client
    V3.0.4
    Nov 15 15:45:50 skamis dhclient: Copyright 2004-2006 Internet Systems
    Consortium.
    Nov 15 15:45:50 skamis dhclient: All rights reserved.
    Nov 15 15:45:50 skamis dhclient: For info, please visit
    http://www.isc.org/sw/dhcp/
    Nov 15 15:45:50 skamis dhclient:
    Nov 15 15:45:50 skamis dhclient: Listening on LPF/eth0/00:04:75:dc:7e:9b
    Nov 15 15:45:50 skamis dhclient: Sending on LPF/eth0/00:04:75:dc:7e:9b
    Nov 15 15:45:50 skamis dhclient: Sending on Socket/fallback
    Nov 15 15:45:50 skamis dhclient: DHCPRELEASE on eth0 to 213.66.199.1 port 67
    Nov 15 15:45:50 skamis dhclient: send_packet: Network is unreachable
    Nov 15 15:45:50 skamis dhclient: send_packet: please consult README file
    regarding broadcast address.
    Nov 15 15:45:50 skamis avahi-daemon[4047]: Withdrawing address record
    for 169.254.81.0 on eth0.
    Nov 15 15:45:50 skamis dhclient: receive_packet failed on eth0: Network
    is down
    Nov 15 15:45:50 skamis avahi-daemon[4047]: Leaving mDNS multicast group
    on interface eth0.IPv4 with address 169.254.81.0.
    Nov 15 15:45:50 skamis avahi-daemon[4047]: iface.c:
    interface_mdns_mcast_join() called but no local address available.
    Nov 15 15:45:50 skamis avahi-daemon[4047]: Interface eth0.IPv4 no longer
    relevant for mDNS.
    Nov 15 15:45:50 skamis NetworkManager: ^ISWITCH:
    terminating current connection 'eth0' because it's no longer valid.
    Nov 15 15:45:50 skamis NetworkManager: ^IDeactivating
    device eth0.
    Nov 15 15:45:50 skamis NetworkManager: nm_device_is_802_3_ethernet:
    assertion `dev != NULL' failed
    Nov 15 15:45:50 skamis NetworkManager: nm_device_is_802_11_wireless:
    assertion `dev != NULL' failed
    Nov 15 15:45:58 skamis dhclient: Internet Systems Consortium DHCP Client
    V3.0.4
    Nov 15 15:45:58 skamis dhclient: Copyright 2004-2006 Internet Systems
    Consortium.
    Nov 15 15:45:58 skamis dhclient: All rights reserved.
    Nov 15 15:45:58 skamis dhclient: For info, please visit
    http://www.isc.org/sw/dhcp/
    Nov 15 15:45:58 skamis dhclient:
    Nov 15 15:45:58 skamis kernel: eth0: setting full-duplex.
    Nov 15 15:45:58 skamis dhcdbd: message_handler: message handler not
    found under /com/redhat/dhcp/eth0 for sub-path eth0.dbus.get.reason
    Nov 15 15:45:58 skamis NetworkManager: ^IWill activate
    wired connection 'eth0' because it now has a link.
    Nov 15 15:45:58 skamis NetworkManager: ^ISWITCH: no current
    connection, found better connection 'eth0'.
    Nov 15 15:45:58 skamis dhcdbd: message_handler: message handler not
    found under /com/redhat/dhcp/eth0 for sub-path eth0.dbus.get.reason
    Nov 15 15:45:58 skamis NetworkManager: ^IWill activate
    connection 'eth0'.
    Nov 15 15:45:58 skamis NetworkManager: ^IDevice eth0
    activation scheduled...
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    started...
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 1 of 5 (Device Prepare) scheduled...
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 1 of 5 (Device Prepare) started...
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 2 of 5 (Device Configure) scheduled...
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 1 of 5 (Device Prepare) complete.
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 2 of 5 (Device Configure) starting...
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 2 of 5 (Device Configure) successful.
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 3 of 5 (IP Configure Start) scheduled.
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 2 of 5 (Device Configure) complete.
    Nov 15 15:45:58 skamis NetworkManager: ^IActivation (eth0)
    Stage 3 of 5 (IP Configure Start) started...
    Nov 15 15:45:59 skamis NetworkManager: ^IActivation (eth0)
    Beginning DHCP transaction.
    Nov 15 15:45:59 skamis NetworkManager: ^IActivation (eth0)
    Stage 3 of 5 (IP Configure Start) complete.
    Nov 15 15:45:59 skamis NetworkManager: ^IDHCP daemon state
    is now 12 (successfully started) for interface eth0
    Nov 15 15:45:59 skamis dhclient: Listening on LPF/eth0/00:04:75:dc:7e:9b
    Nov 15 15:45:59 skamis dhclient: Sending on LPF/eth0/00:04:75:dc:7e:9b
    Nov 15 15:45:59 skamis dhclient: Sending on Socket/fallback
    Nov 15 15:46:01 skamis dhclient: DHCPDISCOVER on eth0 to 255.255.255.255
    port 67 interval 4
    Nov 15 15:46:01 skamis dhclient: DHCPOFFER from 213.66.199.1
    Nov 15 15:46:01 skamis dhclient: DHCPREQUEST on eth0 to 255.255.255.255
    port 67
    Nov 15 15:46:01 skamis dhclient: DHCPACK from 213.66.199.1
    Nov 15 15:46:01 skamis avahi-daemon[4047]: New relevant interface
    eth0.IPv4 for mDNS.
    Nov 15 15:46:01 skamis avahi-daemon[4047]: Joining mDNS multicast group
    on interface eth0.IPv4 with address 213.66.199.118.
    Nov 15 15:46:01 skamis avahi-daemon[4047]: Registering new address
    record for 213.66.199.118 on eth0.
    Nov 15 15:46:01 skamis dhclient: bound to 213.66.199.118 -- renewal in
    525 seconds.
    Nov 15 15:46:01 skamis avahi-daemon[4047]: Got SIGTERM, quitting.
    Nov 15 15:46:01 skamis avahi-daemon[4047]: Leaving mDNS multicast group
    on interface eth3.IPv4 with address 192.168.3.103.
    Nov 15 15:46:01 skamis avahi-daemon[4047]: Leaving mDNS multicast group
    on interface eth2.IPv4 with address 192.168.2.102.
    Nov 15 15:46:01 skamis avahi-daemon[4047]: Leaving mDNS multicast group
    on interface eth1.IPv4 with address 192.168.1.101.
    Nov 15 15:46:01 skamis avahi-daemon[4047]: Leaving mDNS multicast group
    on interface eth0.IPv4 with address 213.66.199.118.
    Nov 15 15:46:01 skamis avahi: Avahi detected that your currently
    configured local DNS server serves
    Nov 15 15:46:01 skamis avahi: a domain .local. This is inherently
    incompatible with Avahi and thus
    Nov 15 15:46:01 skamis avahi: Avahi disabled itself. If you want to use
    Avahi in this network, please
    Nov 15 15:46:01 skamis avahi: contact your administrator and convince
    him to use a different DNS domain,
    Nov 15 15:46:01 skamis avahi: since .local should be used exclusively
    for Zeroconf technology.
    Nov 15 15:46:01 skamis avahi: For more information, see
    http://avahi.org/wiki/AvahiAndUnicastDotLocal
    Nov 15 15:46:02 skamis avahi: Avahi detected that your currently
    configured local DNS server serves
    Nov 15 15:46:02 skamis avahi: a domain .local. This is inherently
    incompatible with Avahi and thus
    Nov 15 15:46:02 skamis avahi: Avahi disabled itself. If you want to use
    Avahi in this network, please
    Nov 15 15:46:02 skamis avahi: contact your administrator and convince
    him to use a different DNS domain,
    Nov 15 15:46:02 skamis avahi: since .local should be used exclusively
    for Zeroconf technology.
    Nov 15 15:46:02 skamis avahi: For more information, see
    http://avahi.org/wiki/AvahiAndUnicastDotLocal
    Nov 15 15:46:04 skamis dhclient: DHCPDISCOVER on eth0 to 255.255.255.255
    port 67 interval 8
    Nov 15 15:46:04 skamis dhclient: DHCPOFFER from 213.66.199.1
    Nov 15 15:46:04 skamis dhclient: DHCPREQUEST on eth0 to 255.255.255.255
    port 67
    Nov 15 15:46:04 skamis dhclient: DHCPACK from 213.66.199.1
    Nov 15 15:46:04 skamis dhclient: bound to 213.66.199.118 -- renewal in
    530 seconds.
    Nov 15 15:46:08 skamis kernel: eth0: no IPv6 routers present
    Nov 15 15:46:13 skamis dhclient: DHCPREQUEST on eth0 to 213.66.199.1 port 67
    Nov 15 15:46:13 skamis dhclient: DHCPACK from 213.66.199.1
    Nov 15 15:46:13 skamis dhclient: bound to 213.66.199.118 -- renewal in
    541 seconds.
    Nov 15 15:46:44 skamis NetworkManager: ^IDevice 'eth0' DHCP
    transaction took too long (>45s), stopping it.
    Nov 15 15:46:44 skamis dhclient: There is already a pid file
    /var/run/dhclient.eth0.pid with pid 5704
    Nov 15 15:46:44 skamis dhclient: killed old client process, removed PID file
    Nov 15 15:46:44 skamis dhclient: DHCPRELEASE on eth0 to 213.66.199.1 port 67
    Nov 15 15:46:45 skamis NetworkManager: ^IActivation (eth0)
    Stage 4 of 5 (IP Configure Timeout) scheduled...
    Nov 15 15:46:45 skamis NetworkManager: ^IDHCP daemon state
    is now 14 (normal exit) for interface eth0
    Nov 15 15:46:45 skamis NetworkManager: ^IDHCP daemon state
    is now 14 (normal exit) for interface eth0
    Nov 15 15:46:45 skamis NetworkManager: ^IActivation (eth0)
    Stage 4 of 5 (IP Configure Timeout) started...
    Nov 15 15:46:45 skamis NetworkManager: ^INo DHCP reply
    received. Automatically obtaining IP via Zeroconf.
    Nov 15 15:46:45 skamis NetworkManager: ^Iautoip: Sending
    probe #0 for IP address 169.254.81.0.
    Nov 15 15:46:45 skamis NetworkManager: ^Iautoip: Waiting
    for reply...
    Nov 15 15:46:47 skamis NetworkManager: ^Iautoip: Sending
    probe #1 for IP address 169.254.81.0.
    Nov 15 15:46:47 skamis NetworkManager: ^Iautoip: Waiting
    for reply...
    Nov 15 15:46:49 skamis NetworkManager: ^Iautoip: Sending
    probe #2 for IP address 169.254.81.0.
    Nov 15 15:46:49 skamis NetworkManager: ^Iautoip: Waiting
    for reply...
    Nov 15 15:46:52 skamis NetworkManager: ^Iautoip: Sending
    announce #0 for IP address 169.254.81.0.
    Nov 15 15:46:52 skamis NetworkManager: ^Iautoip: Waiting
    for reply...
    Nov 15 15:46:55 skamis NetworkManager: ^Iautoip: Sending
    announce #1 for IP address 169.254.81.0.
    Nov 15 15:46:55 skamis NetworkManager: ^Iautoip: Waiting
    for reply...
    Nov 15 15:46:58 skamis NetworkManager: ^Iautoip: Sending
    announce #2 for IP address 169.254.81.0.
    Nov 15 15:46:58 skamis NetworkManager: ^Iautoip: Waiting
    for reply...
    Nov 15 15:47:01 skamis NetworkManager: ^IActivation (eth0)
    Stage 5 of 5 (IP Configure Commit) scheduled...
    Nov 15 15:47:01 skamis NetworkManager: ^IActivation (eth0)
    Stage 4 of 5 (IP Configure Timeout) complete.
    Nov 15 15:47:01 skamis NetworkManager: ^IActivation (eth0)
    Stage 5 of 5 (IP Configure Commit) started...
    Nov 15 15:47:02 skamis NetworkManager: ^IClearing nscd
    hosts cache.
    Nov 15 15:47:02 skamis NetworkManager: ^I nm_spawn_process ():
    nm_spawn_process('/usr/sbin/nscd -i hosts'): could not spawn process.
    (Failed to execute child process "/usr/sbin/nscd" (No such file or
    directory))
    Nov 15 15:47:02 skamis NetworkManager: ^IActivation (eth0)
    successful, device activated.
    Nov 15 15:47:02 skamis NetworkManager: ^IActivation (eth0)
    Finish handler scheduled.
    Nov 15 15:47:02 skamis NetworkManager: ^IActivation (eth0)
    Stage 5 of 5 (IP Configure Commit) complete.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Found user 'avahi' (UID 104)
    and group 'avahi' (GID 105).
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Successfully dropped root
    privileges.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: avahi-daemon 0.6.16 starting up.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Successfully called chroot().
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Successfully dropped
    remaining capabilities.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: No service found in
    /etc/avahi/services.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: New relevant interface
    eth3.IPv4 for mDNS.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Joining mDNS multicast group
    on interface eth3.IPv4 with address 192.168.3.103.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: New relevant interface
    eth2.IPv4 for mDNS.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Joining mDNS multicast group
    on interface eth2.IPv4 with address 192.168.2.102.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: New relevant interface
    eth1.IPv4 for mDNS.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Joining mDNS multicast group
    on interface eth1.IPv4 with address 192.168.1.101.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: New relevant interface
    eth0.IPv4 for mDNS.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Joining mDNS multicast group
    on interface eth0.IPv4 with address 169.254.81.0.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Network interface enumeration
    completed.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Registering new address
    record for 192.168.3.103 on eth3.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Registering new address
    record for 192.168.2.102 on eth2.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Registering new address
    record for 192.168.1.101 on eth1.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Registering new address
    record for 169.254.81.0 on eth0.
    Nov 15 15:47:03 skamis avahi-daemon[5831]: Registering HINFO record with
    values 'I686'/'LINUX'.
    Nov 15 15:47:04 skamis avahi-daemon[5831]: Server startup complete. Host
    name is skamis.local. Local service cookie is 1032625664.
    Nov 15 15:47:13 skamis kernel: eth0: no IPv6 routers present



    ----
    AAW wrote:
    > Hi,
    >
    > I’m having a few network problems that I would appreciate some

    pointers on solutions.
    >
    > I have a server running debian linux, which has been working for a

    few months now. But I have recently encountered a few problems. The
    server is connected to the internet via an ADSL modem and gets its IP
    via DHCP from my ISP. Connected to it on the internal network are two PC
    running windows XP and a due boot laptop running Linux / windows XP.
    >
    > The problems I am having are:
    >
    > 1. Losing IP number. When I boot up I get an IP number from my ISP

    with a time out of 400 – 600 seconds. My connection to the internet
    lasts for about 5 minutes then I lose the connection. When I run
    ifconfig I see I have lost my IP address provided by my ISP and have an
    address have an address starting with 169. This problem started on
    Saturday evening but cleared up itself on Sunday morning. Things were
    working fine again until Wednesday evening when the problem reoccurred.
    This made me think it was a problem with my ISP but they didn’t seam to
    have a clue what the problem could be. So I check if the windows machine
    running XP can connect and it can. No problems in windows. What I would
    like to know is; is this a problem with my server or my ISP Why does it
    work under windows but not linux? If the problem is with my sever, how
    do I find out what the problem is and fix it?
    >

    My first resort would be to do a reinstall of the dhcp client software.
    Also, There will be log messages somewhere in /var/log/ (daemon.log on
    my firewall) giving details of the link state and any negotiation messages.
    > 2. This is related to the first problem. When I lose connection to

    my ISP I also lose connection to all computers on the internal network.
    I get “network unreachable” errors even with the server. I thought this
    might be a DNS problem as I’m using my ISP’s DNS. However, after
    setting up DNS on my server and using that the problem remains. Any
    ideas what could cause it and how to fix it?
    >

    This part should be independent of 1 unless the dhcp client is upsetting
    things. First call would be the output of ifconfig and route -n under
    both conditions (with and without the IP), I'd also check
    /etc/network/interfaces
    /etc/[network|ppp]/ip-[down|up].d/
    and any scripts associated with your modem driver.

    --
    Keith Blow

  7. Re: a few network problems

    AAW wrote:
    > I did an uninstall and a reinstall but no change. So I have had a look
    > at the logs. I can see that it gets its IP address from my ISP :
    >
    > Nov 15 15:46:04 skamis dhclient: bound to 213.66.199.118 -- renewal in
    > 530 seconds.
    >
    > and then I can see that it loses its address :
    >
    > Nov 15 15:46:44 skamis dhclient: DHCPRELEASE on eth0 to 213.66.199.1
    > port 67
    >
    > ...
    >
    > Iautoip: Sending probe #0 for IP address 169.254.81.0.
    >
    >
    > but I don't really follow why. One thing I note in the log is the bit
    > about "Avahi detected that your currently configured local DNS server
    > serves a domain .local" leading to "Avahi disabled itself". Could this
    > be the source of the problem?
    >
    > Part of the log is bellow. Does it help to work out why I lose my IP
    > address?
    >
    > Thanks for your time.
    >
    > log -----
    >
    > --deleted

    It could be. A while ago I had a machine on my network which
    automatically installed zeroconf during an upgrade. Everything broke and
    normal service resumed once I deleted it. It looks like the problem is
    that both avahi-daemon and dhcp are trying to manage the eth0 interface.
    My next guess, if you don't want to remove avahi etc, is to look at the
    conf files and see if you can exclude eth0 from its control. I just had
    a quick look at the avahi packages and there is one called avahi-autoipd
    which is a daemon which automatically configures local IP addresses.
    This may be the problem. Also, you have avahi-daemon running which is
    something to do with auto configuration. I don't have either of these
    installed (or zeroconf).

    Looking at the log it would appear that dhcp managed to update your IP
    address once so I don't think the problem lies there.


    Good luck.

    --
    Keith Blow

  8. Re: a few network problems

    Well, after playing around with it this weekend I found that it looks
    like its NetworkManager that is causing the problem. If I shut down that
    process my network like stays up. No idea why that should cause the problem.

    I shall try and work out what cause the problem with the NetworkManager.
    If I can't I will install it.

    The other two problems still remain. If I lose my ISP connection I lose
    my internal network connection and can't access windows machines from
    windows machines using samba. Any ideas where to start look for those
    two problems? I have looked in the logs for samba and do not get any
    error messages (or any message) when I try to go from one windows
    machine to the other. However, I do have a message in the log that say
    it cannot create a user.

    Thanks.

    Keith Blow wrote:
    > AAW wrote:
    >> I did an uninstall and a reinstall but no change. So I have had a look
    >> at the logs. I can see that it gets its IP address from my ISP :
    >>
    >> Nov 15 15:46:04 skamis dhclient: bound to 213.66.199.118 -- renewal in
    >> 530 seconds.
    >>
    >> and then I can see that it loses its address :
    >>
    >> Nov 15 15:46:44 skamis dhclient: DHCPRELEASE on eth0 to 213.66.199.1
    >> port 67
    >>
    >> ...
    >>
    >> Iautoip: Sending probe #0 for IP address 169.254.81.0.
    >>
    >>
    >> but I don't really follow why. One thing I note in the log is the bit
    >> about "Avahi detected that your currently configured local DNS server
    >> serves a domain .local" leading to "Avahi disabled itself". Could
    >> this be the source of the problem?
    >>
    >> Part of the log is bellow. Does it help to work out why I lose my IP
    >> address?
    >>
    >> Thanks for your time.
    >>
    >> log -----
    >>
    >> --deleted

    > It could be. A while ago I had a machine on my network which
    > automatically installed zeroconf during an upgrade. Everything broke and
    > normal service resumed once I deleted it. It looks like the problem is
    > that both avahi-daemon and dhcp are trying to manage the eth0 interface.
    > My next guess, if you don't want to remove avahi etc, is to look at the
    > conf files and see if you can exclude eth0 from its control. I just had
    > a quick look at the avahi packages and there is one called avahi-autoipd
    > which is a daemon which automatically configures local IP addresses.
    > This may be the problem. Also, you have avahi-daemon running which is
    > something to do with auto configuration. I don't have either of these
    > installed (or zeroconf).
    >
    > Looking at the log it would appear that dhcp managed to update your IP
    > address once so I don't think the problem lies there.
    >
    >
    > Good luck.
    >


  9. Re: a few network problems

    On Nov 19, 8:39 am, AAW wrote:
    > Well, after playing around with it this weekend I found that it looks
    > like its NetworkManager that is causing the problem. If I shut down that
    > process my network like stays up. No idea why that should cause the problem.


    NetworkManager should never be used on a server. A server should have
    all it's interfaces have static adresses (except if the interfacs to
    your ISP uses DHCP to get IP from the ISP, obviously)

    NetworkManager is designed for desktop and laptops with one network
    interface.

    > I shall try and work out what cause the problem with the NetworkManager.
    > If I can't I will install it.


    You should uninstall NetworkManager from your servers.

    > The other two problems still remain. If I lose my ISP connection I lose
    > my internal network connection and can't access windows machines from
    > windows machines using samba. Any ideas where to start look for those
    > two problems?


    Could be that avahi try to controll your ISP-interface, which it
    shouldn't. Avahi is part of Apples Zeroconf, which makes your
    computers announce themself on your local net under the name
    yourhost.local, where yourhost is your computers name.
    It can also set up a linklocal network addres (it's something like
    169.??.0.0/16 I think), if you want to communicate with another
    computer without setting up IP etc. If you use ethernet over
    Firewire, it's good to have too, I guess.
    Quite nice, on a laptop. Not on a server.
    I you distribute your OGG and MP3-files with mt-daapd, your media
    player on that net will be able to play those songs automagically. I
    would configure avahi to only talk to your local network interface.
    Avahi is nice to have on a local net, but not on your ISP net.

    I would guess that NetworkManager and not setting static IP address on
    your servers local network interface is the problem. NetworkManager
    looks into /etc/network/interfaces to see what interfaces it can't
    use. Read the documentation for NetworlManager in /usr/local/doc/
    netw* something.

    Good luck

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