T1 x 2

There's more than one way to accomplish this. If these 2 T1's are going to an ISP they will probably have input has to how they want it setup. In general I believe it depends on what's at the other end.

In one implementation we have an ISP that wanted us to use ppp multilink interfaces to "bond" the two T1's. In another we let the the routing protocol handle it for us.

The real questi>I will get my Cisco 1760 with two WIC-1DSU-T1-V2 tomorrow.

This is the point-to-point lines between two offices to connect two IP networks together. The other end has the same router model and 2 WIC-1DSU-T1-V2.

Thanks,

DT

On both of the serial interfaces on each router, make sure that you include: "no ip route-cache"------this forces per packet process switching, not the normal cache table lookup that is flow orientated---one destination ip address uses one serial link and another destination address uses the other serial link.

Please watch for problems with routing protocols--if you have a small network with a hub and only a couple of remote sites (spokes) then static routes will work just fine and obviate any complications caused by the IRPs.

Also note that some older protocols (like NFS over UDP) do not like out of order packets caused by multiple routes to a destination. I have setup, what you are asking about and have had zero problems

With per packet process switching the router cpu is utilized significantly more than the default mode. You might want to watch cpu utilization--sustained operation above 80% is an area of concern.

Perform a traceroute from a unix class machine and you will see the packets alternating between the two serial links (assuming numbered links). Unix traceroute uses high udp ports, whereas Windows uses ICMP--The AIX unix that I use shows the above behavour much better than the Windows tracert command.

The traceroute in the Cisco IOS produced the following output:

Cisco1605R#traceroute ip 172.17.3.11

Type escape sequence to abort. Tracing the route to 172.17.3.11

1 router.net-fix.com (192.168.254.254) 4 msec 4 msec 0 msec 2 nts01.net-fix.com (192.168.254.1) 4 msec 4 msec 4 msec 3 192.168.254.227 36 msec 56 msec 32 msec 4 65.192.64.94 40 msec 64 msec 36 msec 5 172.17.253.13 40 msec 64 msec 40 msec 6 172.17.2.253 40 msec 64 msec 40 msec 7 172.17.253.6 44 msec 68 msec I think I can set up each WIC separately for ip routing but do not know

It is better to enable cef and use "ip load sharing per-packet". This way you are not using the processor to switch the packets. It's faster and less cpu intensive.

Amy.

Amy,

Your right, but the question was about using a Cisco 1760 with two Serial I/Fs. I don't think cef is supported on this unit---but if it is-you are correct,

Digital Doug

Hi Doug and Amy, thanks for the advice.

If I update the routers ot the lastest IOS, they will support the CEF, won't they ? The routers will come to me later today or tomorrow. I will try and report back.

Thanks again,

DT

Well, I just tested cef on a 2524 and 2620XM---worked fine.. Does not work on a 1605-R. Amy is right- the cef does a nice job on units that support it---way lower cpu utilization.

1760 supports ip cef from 12.2T and above.

Amy.

Digital Doug wrote:

destination ip

That's a good news for me. My two routers arrived and they have

12.2.something. I will try them this weekend.

DT