Problem to be solved

suresharja · ‎10-13-2004

Hi All,

Two locations connected by two links(one is leased line the other is VPN-MPLS) and using 3745 routers both sides.I learnt that Fast switching is enabled BYDEFAULT. If that is the case , I see some packets via leased line and some via VPN(Using Extended ping).I want to disable per packet load balancing and enable per session load balancing. How can I do that???

Thanks In Advance...

suresh arja

Kevin Dorrell · ‎10-13-2004

Suresh,

Fast switching implies per-session load balancing already. If you disable fast switching, then you will get per-packet load balancing.

To disactivate fast switching, do no ip route-cache on the ingress interface. Note this only affects traffic going out from the (other side of the) box, not traffic coming into it.

If you have CEF enabled, then it can handle per-packet or per-session. You can find the details in this document:

http://www.cisco.com/en/US/tech/tk827/tk831/technologies_tech_note09186a0080094806.shtml

Kevin Dorrell

Luxembourg

suresharja · ‎10-13-2004

Hi Kevin,

When it is per-session load balancing , I used extended ping to see the path , my router is sending one packet on leased line next on VPN line.Why will this happen????

Thanks for your reply..

suresh arja

a.awan · ‎10-13-2004

Packets generated by the router are process switched and for process switching the load balancing is on a per packet basis.

Try to focus on traffic using the router as a transit rather then traffic being sourced by the router.

suresharja · ‎10-13-2004

Hi,

I tried ping from one of linux systems using "ping -R ipaddress" even then I see some packets are going through leased line some are through VPN. Why this should happen?? I tried with all options like "IP ROUTE-CACHE, IP ROUTE-CACHE CEF, IP ROUTE-CACHE SAME-INTERFACE" , BUT no use, packets are sent on both links... can you suggest a solution.

Thanks...

suresh arja

a.awan · ‎10-13-2004

Are you sure it is not the return traffic you are seeing come back via the second link?

Turn on cef and post the output of your config, sh ip route, show ip cef, show ip cef .

suresharja · ‎10-13-2004

Hi ,

Sure, I am posting ping -R result.

# ping -R 10.133.13.1

PING 10.133.13.1 (10.133.13.1): 56 data bytes

64 bytes from 10.133.13.1: icmp_seq=0 ttl=253 time=210 ms

RR: 172.16.1.229

172.16.10.1

10.133.13.1

172.16.10.2

172.16.1.230

10.128.1.1

hydpa01.sail.com (10.128.1.6)

64 bytes from 10.133.13.1: icmp_seq=1 ttl=253 time=100 ms

RR: 172.16.0.1

172.16.10.1

10.133.13.1

172.16.10.2

172.16.0.2

10.128.1.1

hydpa01.sail.com (10.128.1.6)

64 bytes from 10.133.13.1: icmp_seq=2 ttl=253 time=180 ms

RR: 172.16.1.229

172.16.10.1

10.133.13.1

172.16.10.2

172.16.1.230

10.128.1.1

hydpa01.sail.com (10.128.1.6)

64 bytes from 10.133.13.1: icmp_seq=3 ttl=253 time=100 ms

RR: 172.16.0.1

172.16.10.1

10.133.13.1

172.16.10.2

172.16.0.2

10.128.1.1

hydpa01.sail.com (10.128.1.6)

64 bytes from 10.133.13.1: icmp_seq=4 ttl=253 time=150 ms

RR: 172.16.1.229

172.16.10.1

10.133.13.1

172.16.10.2

172.16.1.230

10.128.1.1

hydpa01.sail.com (10.128.1.6)

Router Configuration:

sailhyd#sh ip route 10.133.0.0

Routing entry for 10.133.0.0/16

Known via "static", distance 1, metric 0 (connected)

Routing Descriptor Blocks:

directly connected, via Tunnel5

Route metric is 0, traffic share count is 1

* directly connected, via Serial1/0

Route metric is 0, traffic share count is 1

Regards...

suresh arja

suresharja · ‎10-14-2004

Hi,

I have posted the configuration.Kindly through some light on this.

suresh arja

a.awan · ‎10-14-2004

I did not see any cef related outputs in your posting. Kindly provide that information along with the IOS version you are running.

suresharja · ‎10-14-2004

Hi,

Iam attaching " SHOW IP CEF S1/0",

sailhyd#sh ip cef s1/0

Prefix Next Hop Interface

10.133.0.0/16 attached Tunnel5

attached Serial1/0

172.16.0.0/30 attached Serial1/0

172.16.0.2/32 attached Serial1/0

192.1.100.35/32 172.16.0.2 Serial1/0

192.1.100.39/32 attached Serial1/0

192.1.100.43/32 attached Serial1/0

192.1.100.91/32 attached Serial1/0

192.1.100.171/32 172.16.0.2 Serial1/0

192.1.101.35/32 172.16.0.2 Serial1/0

192.180.35.0/24 172.16.0.2 Serial1/0

192.180.39.0/24 attached Serial1/0

192.180.43.0/24 attached Serial1/0

192.180.101.0/24 172.16.0.2 Serial1/0

sailhyd#sh ip cef tunn5

Prefix Next Hop Interface

10.133.0.0/16 attached Tunnel5

attached Serial1/0

172.16.1.228/30 attached Tunnel5

sailhyd#

kindly look into this...

suresh arja

suresharja · ‎10-14-2004

hi ,

IOS VER is :

ROM: System Bootstrap, Version 12.2(8r)T2, RELEASE SOFTWARE (fc1)

Configuration register is 0x2102

suresh arja

suresharja · ‎10-14-2004

Hi ,

I have posted the ver and sh ip cef.....

kindly look into this...

suresh arja

a.awan · ‎10-17-2004

Can you also provide the output of the following commands as they are typed below. I will appreciate if you provide the output of the exact commands and not something else:

1. show ip cef 10.133.0.0 internal

2. show ip cef 10.133.0.0

3. show cef interface serial 0/1

4. show cef interface tunnel 5

5. show adjacency detail

suresharja · ‎10-17-2004

Hi ,

Pls. find attachment of the output oc the commands.

suresh arja

suresharja · ‎10-18-2004

Hi,

Kindly look into the problem and through some light...

suresh arja