Best approach for a dual-ADSL FreeBSD Internet router? - BSD

This is a discussion on Best approach for a dual-ADSL FreeBSD Internet router? - BSD ; Hi, My ISP is offering a dual ADSL feed at a good price. They can route traffic to my public /28 IP block via both ADSL routers on a load-balanced basis. If one ADSL line fails, they can stop routing ...

+ Reply to Thread
Results 1 to 4 of 4

Thread: Best approach for a dual-ADSL FreeBSD Internet router?

  1. Best approach for a dual-ADSL FreeBSD Internet router?

    Hi,

    My ISP is offering a dual ADSL feed at a good price. They can route
    traffic to my public /28 IP block via both ADSL routers on a
    load-balanced basis. If one ADSL line fails, they can stop routing
    traffic through it after a couple of seconds, and then re-start when it
    comes back up. This should provide more speed and more reliability up
    to a point.

    Packets destined for my public IP block could arrive through either
    router at any time, and similarly the ISP would accept packets for the
    Internet from either router at any time. That is, both routers can
    process traffic at once (with the caveat that this can lead to
    out-of-order delivery, possibly problematic for VOIP).

    I would like to build a FreeBSD router to aggregate the two ADSL routers
    to offer a single Internet gateway to the rest of my network. It's OK
    if outbound traffic favours one link, but if outbound load-balancing was
    possible, that would be ideal.

    The ADSL routers would be Cisco 877's with the full IOS on them
    (Advanced IP Services, probably 12.4(20)T if it seems stable). So they
    should offer a fair selection of routing protocols.

    I just wondered what the best approach would be, in order to build a
    FreeBSD router to perform load-balancing over the two ADSL links, with
    correct routing when one of the ADSL lines fails.

    I'd be grateful for any thoughts on the options available.

    Cheers,

    - Martin.

  2. Re: Best approach for a dual-ADSL FreeBSD Internet router?

    Martin Johnson wrote:

    > I'd be grateful for any thoughts on the options available.


    Answering own post (sure sign of madness)...

    On further consideration, one tricky problem is that a FreeBSD router
    cannot know the state of each ADSL line in terms of
    bandwidth/latency/queue length. At least, not without some pretty heroic
    SNMP action. So it cannot really load-balance outbound traffic without
    some risk of packet loss.

    An alternative approach would be to go for an ADSL router with two ADSL
    ports. The only two such models I can find are:-

    1) "ZyXEL P-663H High Performance Dual ADSL 2+ WAN Router" - approx 300
    UKP (600 USD). Low price but it does most things including Annex M
    support. Probably lacks IPV6 support (though few UK ISPs support that).

    2) Cisco 1841 router. Hard to price accurately given the range of IOS
    options and the need to purchase two ADSL WIC modules. Cost for a
    dual-ADSL model probably in the range 800 UKP (1600 USD) to 1100 UKP
    (2200 USD) although I did see a suspiciously cheap one from a
    supposedly-reputable EBay trader recently.

    The snags here are that a cheap dual-feed ADSL router like the Zyxel
    might be less stable than a single Cisco ADSL router, while the Cisco
    1841 just looks too pricey. Of course, any dual ADSL router is a SPOF
    (Single Point Of Failure), but at least ADSL line failover would stand a
    chance of working properly.

    - Martin.

  3. Re: Best approach for a dual-ADSL FreeBSD Internet router?

    Martin Johnson schrieb:
    > Hi,

    [...]
    > I'd be grateful for any thoughts on the options available.



    Checked out pfsense already?
    www.pfsense.org



    cheers,
    Rainer

  4. Re: Best approach for a dual-ADSL FreeBSD Internet router?

    On Sun, 21 Sep 2008 18:40:30 +0100, Martin Johnson wrote:

    > Hi,
    >
    > My ISP is offering a dual ADSL feed at a good price. They can route
    > traffic to my public /28 IP block via both ADSL routers on a
    > load-balanced basis. If one ADSL line fails, they can stop routing
    > traffic through it after a couple of seconds, and then re-start when it
    > comes back up. This should provide more speed and more reliability up
    > to a point.
    >
    > Packets destined for my public IP block could arrive through either
    > router at any time, and similarly the ISP would accept packets for the
    > Internet from either router at any time. That is, both routers can
    > process traffic at once (with the caveat that this can lead to
    > out-of-order delivery, possibly problematic for VOIP).
    >
    > I would like to build a FreeBSD router to aggregate the two ADSL routers
    > to offer a single Internet gateway to the rest of my network. It's OK
    > if outbound traffic favours one link, but if outbound load-balancing was
    > possible, that would be ideal.


    If you already have a couple of lines with a router on each one and
    want to do "link aggregation", also known as "port trunking", why
    don't you just get a switch?

    NetGear FS726T
    http://www.netgear.com/Products/Swit...es/FS726T.aspx
    Has PoE and CoS to enable VOIP use
    List price 189.99, street price around $170.00

    >
    > The ADSL routers would be Cisco 877's with the full IOS on them
    > (Advanced IP Services, probably 12.4(20)T if it seems stable). So they
    > should offer a fair selection of routing protocols.
    >
    > I just wondered what the best approach would be, in order to build a
    > FreeBSD router to perform load-balancing over the two ADSL links, with
    > correct routing when one of the ADSL lines fails.
    >
    > I'd be grateful for any thoughts on the options available.
    >
    > Cheers,
    >
    > - Martin.



+ Reply to Thread