[c-nsp] ip cef load sharing

[Dan Letkeman]

My only options for the IP CEF command are as follows:

  original   Original algorithm
  tunnel     Algorithm for use in tunnel only environments
  universal  Algorithm for use in most environments

I tried original, and it seems as if it load balances, but it doesn't
switch from modem to modem very fast.  But in any case there is a lot
less problems with this on.

I also found out that the content filter that is before the cisco
router is also doing NAT.  I'm assuming that's a problem as well
because now the router doesn't know what the source IP is anymore.

Any other ideas on how to make this work better?

Thanks,
Dan.

On Sat, Aug 16, 2008 at 6:35 PM, Ben Steele <ben.steele at internode.on.net> wrote:
> Dan the reason your having issues is not MTU related, it's NAT related,
> because you have 3 ADSL lines each doing NAT against a different outside IP
> when you turn on per-packet load sharing you end up with flows to the same
> destination having different source IP addresses.
>
> Your only option is per-destination load balancing (ie the default), one way
> you can tweak this a little without breaking to much is to change the
> standard algorithm to include ports.
>
> Try adding "ip cef load-sharing algorithm include-ports destination" into
> your global config once you've removed your per-packet load sharing and see
> how you go.
>
> You are never going to get perfect load balancing in your scenario but if
> you have enough hosts on your LAN it should be sufficient enough, one way
> you can do per-packet is if you get another IP routed down all 3 adsl lines
> and put it on a loopback and NAT everything against that.
>
> Ben
>
> ----- Original Message ----- From: "Dan Letkeman" <danletkeman at gmail.com>
> To: "Rodney Dunn" <rodunn at cisco.com>; <cisco-nsp at puck.nether.net>
> Sent: Saturday, August 16, 2008 3:29 AM
> Subject: Re: [c-nsp] ip cef load sharing
>
>
>> Still seem to have the same problem even with this:
>>
>> interface FastEthernet0/0
>> ip address 10.1.10.1 255.255.255.0
>> ip tcp adjust-mss 1300
>> duplex auto
>> speed auto
>>
>>
>> interface FastEthernet0/1
>> ip address 192.168.10.1 255.255.255.0
>> ip load-sharing per-packet
>> duplex auto
>> speed auto
>>
>> Dan.
>>
>> On Fri, Aug 15, 2008 at 12:49 PM, Rodney Dunn <rodunn at cisco.com> wrote:
>>>
>>> On Fri, Aug 15, 2008 at 12:35:01PM -0500, Dan Letkeman wrote:
>>>>
>>>> ip load-sharing per-packet
>>>>
>>>> I tried adding this to F0/1 and the trace route works now(it randomly
>>>> picks either line), but there seems to be issues with maybe the MTU?
>>>> If I try to browse websites i get page errors and some of the pictures
>>>> and pages don't load.
>>>
>>> Yep...try configuring "ip tcp adjust-mss 1300" or so on the
>>> ingress interface from the LAN.
>>>
>>>>
>>>> Any ideas?
>>>>
>>>> Thanks,
>>>> Dan.
>>>>
>>>> On Fri, Aug 15, 2008 at 12:12 PM, Rodney Dunn <rodunn at cisco.com> wrote:
>>>> > Try ip load-sharing per-packet on both egress interfaces.
>>>> >
>>>> > On Fri, Aug 15, 2008 at 12:00:46PM -0500, Dan Letkeman wrote:
>>>> >> Hello,
>>>> >>
>>>> >> I have a 2621 router running 12.3(26) and I would like to setup load
>>>> >> sharing to multiple adsl lines.  When I do a traceroute on the router
>>>> >> it randomly picks a dsl line and seems to work fine.  But when I do
>>>> >> traceroute tests from a workstation it always seems to take the same
>>>> >> adsl line.  Is there something else I need to add to the >>
>>>> >> configuration
>>>> >> to make it pick random lines, or is there a timeout of some sorts
>>>> >> before it will select the next ip route
>>>> >>
>>>> >> Here is my config:
>>>> >>
>>>> >> !
>>>> >> interface FastEthernet0/0
>>>> >>  ip address 10.1.10.1 255.255.255.0
>>>> >>  duplex auto
>>>> >>  speed auto
>>>> >> !
>>>> >> interface FastEthernet0/1
>>>> >>  ip address 192.168.10.1 255.255.255.0
>>>> >>  duplex auto
>>>> >>  speed auto
>>>> >> !
>>>> >> ip http server
>>>> >> ip classless
>>>> >> ip route 0.0.0.0 0.0.0.0 192.168.10.10
>>>> >> ip route 0.0.0.0 0.0.0.0 192.168.10.11
>>>> >> !
>>>> >>
>>>> >> The two adsl modem/routers I have are 192.168.10.10, and >>
>>>> >> 192.168.10.11
>>>> >>
>>>> >> Thanks,
>>>> >> Dan.
>>>> >> _______________________________________________
>>>> >> cisco-nsp mailing list  cisco-nsp at puck.nether.net
>>>> >> https://puck.nether.net/mailman/listinfo/cisco-nsp
>>>> >> archive at http://puck.nether.net/pipermail/cisco-nsp/
>>>> >
>>>
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>
>