Hello All,
This is my first post so please bare with me as I am unsure of all the proper etiquette. I have a remote site which ties back into my network via a site to site VPN which travels across my ISP's cable modem (a 10Mbps link) and terminates at my ASA. This site has been having issues, especially with their Citrix Desktop connection (uses TCP protocol). At the site I had an 1841 router connected to a 2950 switch. Spanning the trunk port and running Wireshark, I could see that during their Citrix session a packet wouldn't make it to the server and the server would send multiple requests to the client for that missing packet. The Citrix session would hang until the client retransmitted the missing packet. There are only three computers at this site. The users cycle through twice a day for about an hour each time. It is only during those times that errors seem to occur. Looking at the 1841:
Show interface fa0/1
FastEthernet0/1 is up, line protocol is up
Hardware is Gt96k FE, address is 0025.457e.7ba5 (bia 0025.457e.7ba5)
Internet address is 10.xxx.xxx.1/24
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:53, output 00:00:00, output hang never
Last clearing of "show interface" counters 20:19:15
Input queue: 0/75/79/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 2000 bits/sec, 9 packets/sec
5 minute output rate 53000 bits/sec, 10 packets/sec
350549 packets input, 26089153 bytes
Received 3081 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
294773 packets output, 65495242 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Show buffers:
Buffer elements:
1118 in free list (1119 max allowed)
566595 hits, 0 misses, 619 created
Public buffer pools:
Small buffers, 104 bytes (total 50, permanent 50, peak 67 @ 1d22h):
50 in free list (20 min, 150 max allowed)
1438573 hits, 502 misses, 24 trims, 24 created
182 failures (0 no memory)
Middle buffers, 600 bytes (total 29, permanent 25, peak 92 @ 2d01h):
27 in free list (10 min, 150 max allowed)
1345094 hits, 822 misses, 137 trims, 141 created
526 failures (0 no memory)
Big buffers, 1536 bytes (total 50, permanent 50, peak 55 @ 2d02h):
50 in free list (5 min, 150 max allowed)
205653 hits, 105 misses, 5 trims, 5 created
70 failures (0 no memory)
VeryBig buffers, 4520 bytes (total 10, permanent 10, peak 14 @ 2d01h):
10 in free list (0 min, 100 max allowed)
3342 hits, 283 misses, 23 trims, 23 created
283 failures (0 no memory)
Large buffers, 5024 bytes (total 1, permanent 0, peak 3 @ 2d01h):
1 in free list (0 min, 10 max allowed)
39 hits, 244 misses, 39 trims, 40 created
244 failures (0 no memory)
Huge buffers, 18024 bytes (total 1, permanent 0, peak 3 @ 2d01h):
1 in free list (0 min, 4 max allowed)
28 hits, 216 misses, 36 trims, 37 created
216 failures (0 no memory)
It seems I am only dropping packets on the link between my switch and my router. The interface to my WAN has no errors. The 2950 also has no errors. What I do not understand is that when I replaced the 2950 with a 3750 (I disabled the L3 with the no ip routing command) for testing purposes, the users no longer experienced their Citrix Desktop sessions freezing. The 1841 continues to report Huge Buffer failures as well as drops on my LAN interface (fa0/1). Why would swapping out the switch solve this problem? I would be extremely appreciative for any information. Also, if you need more information feel free to ask. Thank you!!!
