LAN Degradation

[jdl508]

Hello, I have a serious problem at hand. I have a 2501 that goes to 2 wan sites though a t1. One of the wan sites is having a problem with certain apps (citrix, and other mapped apps) The as400 client works fine. The users can connect to our citrix server over the wan but after a few minutes or and hour (no set time) the prog will just disappear and citrix will pop up a general protocol error 1030 (assuming this means drop in the connection). I did this while doing a ping -t to the server over the wan and it never dropped a packet (icmp) Im dying here as my wan site has been out of prod for 4 days now. I did a debug from a wan client to the citrix server but all you can see are IP packets and it is very hard to diagnose. Also I rebooted the remote router (2621) and it seemed to get better for a while (few hours) then started going back to kicking users from there mapped apps, etc.
thanks for any help
i will supply the config's

2501 (corp site)=================================

CORP#show running-config
Building configuration...

Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname CORP
!
no logging console
enable password 7 05060301351C5C
!
ip subnet-zero
no ip domain-lookup
ipx routing 000c.000c.000c
!
!
!
interface Ethernet0
description connected to EthernetLAN
ip address 128.1.1.50 255.255.255.0
ip directed-broadcast
no ip route-cache
no ip mroute-cache
ipx network A1F9EDDA
!
interface Serial0
description - Connected to Downingtown
ip address 192.168.1.2 255.255.255.252
ip directed-broadcast
encapsulation ppp
no ip route-cache
no ip mroute-cache
ipx network DDD
!
interface Serial1
description - Connected to Broad Street
ip address 192.168.1.5 255.255.255.252
ip directed-broadcast
encapsulation ppp
no ip route-cache
no ip mroute-cache
ipx network BBB
!
router eigrp 100
network 128.1.0.0
network 192.168.1.0
no auto-summary
!
ip classless
ip route 192.168.3.0 255.255.255.0 192.168.1.6
!
!
!
ipx router eigrp 100
network A1F9EDDA
network BBB
network DDD
!
!
ipx router rip
no network DDD
no network BBB
====================================================
remote router (2621)================================
sh run
Building configuration...

Current configuration : 2211 bytes
!
version 12.1
no service single-slot-reload-enable
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname broad-st
!
enable password 7 120A0014000E18447D6B292D3D217201
!
!
!
!
!
ip subnet-zero
no ip domain-lookup
!
ipx routing 000b.000b.000b
!
!
--More--  !
interface FastEthernet0/0
description Broad St Ethernet LAN
ip address 192.168.3.1 255.255.255.0
ip helper-address 128.1.1.17
ip directed-broadcast
shutdown
duplex auto
speed 100
ipx network B encapsulation SAP
!
interface Serial0/0
description Connection to CORP router
ip address 192.168.1.6 255.255.255.252
ip directed-broadcast
encapsulation ppp
shutdown
ipx network BBB
!
interface FastEthernet0/1
no ip address
duplex auto
speed auto
--More--  !
router eigrp 100
network 192.168.1.0
network 192.168.3.0
auto-summary
no eigrp log-neighbor-changes
!
router rip
network 192.168.3.0
!
ip classless
ip http server
!
!
!
ipx router eigrp 100
network BBB
network B
!

 

[wybnormal]

Citrix uses IP yes, but it uses very small packets and it's been well documented that sometimes the default buffer size on the ciscos for small packets is not enough. When the buffer fills, it starts dropping packets. Drop enough you lose the connection.

Check the buffers on the problem router.

router# show buffer

Buffer elements:
471 in free list (500 max allowed)
870696495 hits, 0 misses, 0 created

Public buffer pools:
Small buffers, 104 bytes (total 50, permanent 50):
49 in free list (20 min, 150 max allowed)
27301678 hits, 23 misses, 20 trims, 20 created
0 failures (0 no memory)
:::Snip:::

Look at the failures if any. If there are, you need to tweak the buffers.

http://www.cisco.com/warp/public/63/buffertuning.html

MikeS

Find me at

http://www.packetattack.com

"Take advantage of the enemy's unreadiness, make your way by unexpected routes, and attack unguarded spots."
Sun Tzu

 

[jdl508]

Wybnormal, thanks for the nfo
I ended up moving from the 2501 to a 2621 xm whcih seems to have at least been more forgiving with the problem (100 mb e0 vs. 10mb) anyway I also ended up doing some sap tuning due to the fact novell sap broadcasts occur every min I changed the frequency to 10 min updates. I am also going to keep an eye on the buffers but will wait since i just installed this router to tweak those values. Anyway thanks for the help
jdl