eth0 Not Coming Up - Redhat

This is a discussion on eth0 Not Coming Up - Redhat ; Today I restarted my server to find that it was not responding after 5 minutes. After some investigating, I found that networking was not starting up. Somehow, the /etc/sysconfig/network file had disapeared. This has been corrected and now the network ...

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Thread: eth0 Not Coming Up

  1. eth0 Not Coming Up

    Today I restarted my server to find that it was not responding after 5
    minutes. After some investigating, I found that networking was not starting
    up. Somehow, the /etc/sysconfig/network file had disapeared. This has been
    corrected and now the network service starts successfully along with the lo
    interface. However, I cannot seem to get eth0 to come up. By all accounts,
    it appears to be coming up.

    When I type 'service network restart' it shows:
    Bringing up interface etho: [ OK ]

    Here is my /etc/sysconfig/network file:
    ---
    HOSTNAME=hostname.domain.com
    NETWORKING=yes
    ---

    Here is my ifcfg-eth0 file:
    ---
    DEVICE=eth0
    BOOTPROTO=none
    ONBOOT=yes
    BROADCAST=***.***.170.255
    NETWORK=***.***170.0
    NETMASK=255.255.254.0
    IPADDR=***.***.170.56
    USERCTL=no
    ---

    These files have not changed for several weeks. Up until now, they have
    worked, even after a restart. Can anyone think if any reason why the eth0
    interface would not come up?

    Thank You,
    Jason Williard



  2. Re: eth0 Not Coming Up

    On Mon, 21 Mar 2005 19:58:49 -0800, Jason Williard wrote:
    > Here is my ifcfg-eth0 file:
    > ---
    > DEVICE=eth0
    > BOOTPROTO=none <==== should be static not NONE
    > ONBOOT=yes
    > BROADCAST=***.***.170.255
    > NETWORK=***.***170.0
    > NETMASK=255.255.254.0
    > IPADDR=***.***.170.56
    > USERCTL=no


  3. Re: eth0 Not Coming Up

    "Jason Williard" schreef in bericht
    news:JMidncIDsJU9CqLfRVn-2Q@comcast.com...
    > Today I restarted my server to find that it was not responding after 5
    > minutes. After some investigating, I found that networking was not
    > starting up. Somehow, the /etc/sysconfig/network file had disapeared.
    > This has been corrected and now the network service starts successfully
    > along with the lo interface. However, I cannot seem to get eth0 to come
    > up. By all accounts, it appears to be coming up.
    >
    > When I type 'service network restart' it shows:
    > Bringing up interface etho: [ OK ]
    >
    > Here is my /etc/sysconfig/network file:
    > ---
    > HOSTNAME=hostname.domain.com
    > NETWORKING=yes
    > ---
    >
    > Here is my ifcfg-eth0 file:
    > ---
    > DEVICE=eth0
    > BOOTPROTO=none
    > ONBOOT=yes
    > BROADCAST=***.***.170.255
    > NETWORK=***.***170.0
    > NETMASK=255.255.254.0
    > IPADDR=***.***.170.56
    > USERCTL=no
    > ---
    >
    > These files have not changed for several weeks. Up until now, they have
    > worked, even after a restart. Can anyone think if any reason why the eth0
    > interface would not come up?
    >
    > Thank You,
    > Jason Williard

    Jason,


    On the server can you ping the ipaddress of the server and it's gateway?

    If you can ping the server, but not the gateway then check the cables and
    the NIC settings with mii-tool. NIC settings might conflict with the
    settings of the switch.

    Switch settings might have changed, if you do not manage them.


    Regards,


    Jan Gerrit



  4. Re: eth0 Not Coming Up

    Jason Williard wiped, flushed and then wrote into alt.os.linux.redhat:


    > Here is my ifcfg-eth0 file:
    > ---
    > DEVICE=eth0
    > BOOTPROTO=none
    > ONBOOT=yes
    > BROADCAST=***.***.170.255
    > NETWORK=***.***170.0
    > NETMASK=255.255.254.0
    > IPADDR=***.***.170.56
    > USERCTL=no
    > ---


    BOOTPROTO=static
    BOOTPROTO=dhcp

    Pick one.

    --
    Mr Floppy
    --
    There he goes. One of God's own prototypes. Some kind of high powered mutant
    never even considered for mass production. Too weird to live, and too rare
    to die.
    -Hunter S. Thompson-
    --


  5. Re: eth0 Not Coming Up

    Mr Floppy wiped, flushed and then wrote into alt.os.linux.redhat:

    > Jason Williard wiped, flushed and then wrote into alt.os.linux.redhat:
    >
    >
    >> Here is my ifcfg-eth0 file:
    >> ---
    >> DEVICE=eth0
    >> BOOTPROTO=none
    >> ONBOOT=yes
    >> BROADCAST=***.***.170.255
    >> NETWORK=***.***170.0
    >> NETMASK=255.255.254.0
    >> IPADDR=***.***.170.56
    >> USERCTL=no
    >> ---

    >
    > BOOTPROTO=static
    > BOOTPROTO=dhcp
    >
    > Pick one.
    >


    NETMASK=255.255.255.0

    --
    Mr Floppy
    --
    There he goes. One of God's own prototypes. Some kind of high powered mutant
    never even considered for mass production. Too weird to live, and too rare
    to die.
    -Hunter S. Thompson-
    --


  6. Re: eth0 Not Coming Up

    [Apologies for multiple newsgroups. I've fixed the followup.]

    Jason Williard wrote:
    > Today I restarted my server to find that it was not responding after 5
    > minutes. After some investigating, I found that networking was not starting
    > up. Somehow, the /etc/sysconfig/network file had disapeared. This has been
    > corrected and now the network service starts successfully along with the lo
    > interface. However, I cannot seem to get eth0 to come up. By all accounts,
    > it appears to be coming up.

    Make up your mind :-). Either it's up or it isn't.
    Your note is a little light on symptoms. What is the output of "route
    -n"? "ifconfig -a"? Can you ping your gateway?

    > HOSTNAME=hostname.domain.com
    > NETWORKING=yes

    More to the point, what *is* your gateway? I don't see it defined here
    or in ifcfg-eth0. You need to define it in one place or the other.
    E.g. GATEWAY=xxx.xxx.170.1


    > DEVICE=eth0
    > BOOTPROTO=none

    "Static" is more descriptive, but "none" seems to be SOP for RedHat.
    I've seen lots of systems work just fine with "none" here.

    > ONBOOT=yes
    > BROADCAST=***.***.170.255
    > NETWORK=***.***170.0
    > NETMASK=255.255.254.0

    This is probably OK, depending on what the rest of the IP address is.
    If you know it used to work, don't change it.
    > IPADDR=***.***.170.56
    > USERCTL=no


  7. Re: eth0 Not Coming Up

    "Jason Williard" wrote in message news:...

    [please, control your x-posting impulses]

    > Today I restarted my server to find that it was not responding after 5
    > minutes. After some investigating, I found that networking was not starting
    > up. Somehow, the /etc/sysconfig/network file had disapeared. This has been
    > corrected and now the network service starts successfully along with the lo
    > interface. However, I cannot seem to get eth0 to come up. By all accounts,
    > it appears to be coming up.
    >
    > When I type 'service network restart' it shows:
    > Bringing up interface etho: [ OK ]


    Yep, it's coming up

    > Here is my /etc/sysconfig/network file:
    > ---
    > HOSTNAME=hostname.domain.com
    > NETWORKING=yes
    > ---


    FWIW, mine is different order. Should not matter, I think.

    > Here is my ifcfg-eth0 file:
    > ---


    If this is a RH distro, you will have several ifcfg-eth0 files, and
    depending on whether you've used the gui config tool to make any
    changes. Checked the
    /etc/sysconfig/networking/profiles/default/ifcfg-eth0?

    FWIW, my ifcfg-eth0 files have an explicit "TYPE=Ethernet".

    > DEVICE=eth0
    > BOOTPROTO=none
    > ONBOOT=yes
    > BROADCAST=***.***.170.255
    > NETWORK=***.***170.0
    > NETMASK=255.255.254.0
    > IPADDR=***.***.170.56
    > USERCTL=no
    > ---
    >
    > These files have not changed for several weeks. Up until now, they have
    > worked, even after a restart. Can anyone think if any reason why the eth0
    > interface would not come up?


    I will assume that IP pings fail, ie., something's broke;-)

    The only thing I see that might be broke from provided info is the:
    BROADCAST=***.***.170.255
    This assumes the netmask is accurate.

    Here is how the IP bitmasks/addresses would appear (using 172.16 for
    *.*)

    netmask = 255.255.254.0 = /23
    11111111 11111111 1111111 0 00000000
    ^^^^^^^
    Note the (7) subnet bits in 3rd octet

    network = 172.16.170.000
    10101100 00010000 1010101 0 00000000
    ^^^^^^^^^^
    Note the (9!) "host" bits all zero

    eth0 = 172.16.170.56
    10101100 00010000 1010101 0 00111000

    Broadcast address should have all host bits = 1

    bcast = 172.16.170.255 ???
    10101100 00010000 1010101 0 11111111
    ^^^^^^^^^^
    Not all "host" bits set to 1
    170(dec)=10101010(binary)
    ^
    bcast = 172.16.171.255
    10101100 00010000 1010101 1 11111111
    ^^^^^^^^^^
    All "host" bits set to 1
    171(dec)=10101011(binary)
    ^

    Whether this is the source of your problems, I can't say for sure.

    hth,
    prg

  8. Re: eth0 Not Coming Up

    In article , P Gentry wrote:
    > "Jason Williard" wrote in message news:...
    >
    > [please, control your x-posting impulses]
    >
    >> Today I restarted my server to find that it was not responding after 5
    >> minutes. After some investigating, I found that networking was not starting
    >> up. Somehow, the /etc/sysconfig/network file had disapeared. This has been
    >> corrected and now the network service starts successfully along with the lo
    >> interface. However, I cannot seem to get eth0 to come up. By all accounts,
    >> it appears to be coming up.
    >>
    >> When I type 'service network restart' it shows:
    >> Bringing up interface etho: [ OK ]

    >
    > Yep, it's coming up
    >
    >> Here is my /etc/sysconfig/network file:
    >> ---
    >> HOSTNAME=hostname.domain.com
    >> NETWORKING=yes
    >> ---

    >
    > FWIW, mine is different order. Should not matter, I think.
    >
    >> Here is my ifcfg-eth0 file:
    >> ---

    >
    > If this is a RH distro, you will have several ifcfg-eth0 files, and
    > depending on whether you've used the gui config tool to make any
    > changes. Checked the
    > /etc/sysconfig/networking/profiles/default/ifcfg-eth0?
    >
    > FWIW, my ifcfg-eth0 files have an explicit "TYPE=Ethernet".
    >
    >> DEVICE=eth0
    >> BOOTPROTO=none
    >> ONBOOT=yes
    >> BROADCAST=***.***.170.255
    >> NETWORK=***.***170.0
    >> NETMASK=255.255.254.0
    >> IPADDR=***.***.170.56
    >> USERCTL=no
    >> ---
    >>
    >> These files have not changed for several weeks. Up until now, they have
    >> worked, even after a restart. Can anyone think if any reason why the eth0
    >> interface would not come up?

    >
    > I will assume that IP pings fail, ie., something's broke;-)
    >
    > The only thing I see that might be broke from provided info is the:
    > BROADCAST=***.***.170.255
    > This assumes the netmask is accurate.
    >
    > Here is how the IP bitmasks/addresses would appear (using 172.16 for
    > *.*)
    >
    > netmask = 255.255.254.0 = /23
    > 11111111 11111111 1111111 0 00000000
    > ^^^^^^^
    > Note the (7) subnet bits in 3rd octet
    >
    > network = 172.16.170.000
    > 10101100 00010000 1010101 0 00000000
    > ^^^^^^^^^^
    > Note the (9!) "host" bits all zero
    >
    > eth0 = 172.16.170.56
    > 10101100 00010000 1010101 0 00111000
    >
    > Broadcast address should have all host bits = 1
    >
    > bcast = 172.16.170.255 ???
    > 10101100 00010000 1010101 0 11111111
    > ^^^^^^^^^^
    > Not all "host" bits set to 1
    > 170(dec)=10101010(binary)
    > ^
    > bcast = 172.16.171.255
    > 10101100 00010000 1010101 1 11111111
    > ^^^^^^^^^^
    > All "host" bits set to 1
    > 171(dec)=10101011(binary)
    > ^
    >
    > Whether this is the source of your problems, I can't say for sure.


    In the case where the last octect of the subnet mask is 0, the last octet of
    the broadcast will be 255. I have many systems very similar to the above and
    they all work fine. Its a *broadcast* address, so ALL host bits should be 1...

    Kevin

  9. Re: eth0 Not Coming Up

    Kevin Collins wrote:
    > In the case where the last octect of the subnet mask is 0, the last octet of
    > the broadcast will be 255. I have many systems very similar to the above and
    > they all work fine. Its a *broadcast* address, so ALL host bits should be 1...
    >
    > Kevin

    Not when it's a /23, which is what a netmask of 255.255.254.0 means. [If
    this isn't the correct netmask, the config file you posted is wrong.]
    There are 9 (32-23) zeros on the end, so there are 9 host bits. You
    need to use 9 1 bits for the broadcast address. Read the RFC.

  10. Re: eth0 Not Coming Up

    In article , Allen McIntosh wrote:
    > Kevin Collins wrote:
    >> In the case where the last octect of the subnet mask is 0, the last octet of
    >> the broadcast will be 255. I have many systems very similar to the above and
    >> they all work fine. Its a *broadcast* address, so ALL host bits should be 1...
    >>
    >> Kevin

    > Not when it's a /23, which is what a netmask of 255.255.254.0 means. [If
    > this isn't the correct netmask, the config file you posted is wrong.]
    > There are 9 (32-23) zeros on the end, so there are 9 host bits. You
    > need to use 9 1 bits for the broadcast address. Read the RFC.


    Well, technically, we are both right All I said was the *last octet* of the
    brodcast address should be 255. Notice that in xxx.xxx.170.255 and
    xxx.xxx.171.255 the last octet *IS* 255, although you are of course correct
    about the bits... My fault for not paying closer attention to detail.

    Kevin

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