Slow network response while accesing via MetroEthernet

[enriquebs]

HI all,

When we try to access a 2800 router via MetroEthernet we spend a lot of time until the username and password prompt appears, so... after it the router is working slowly, what I mean is that for example you can not write a command in a fluent way.

It seems a line (MetroEthernet) issue, but the ISP don't tell us any information. Is there any way to check it in the router? I've been trying with the show controllers command but this info is difficult to understand.

Any idea?

Thx a lot in advance.

cheers,

[peterledwidge]

Ensure you have the correct speed and duplex settings for optimal performance, sounds like there maybe a mis match issue.

clear counters ethernet/fastethernet x

sh int ethernet/fastethernet x

Check for errors or late collisions on the link.

Hope this helps.

Regards

Peter

[enriquebs]

HI Peter,

Here is the sh int output:

FastEthernet0/0 is up, line protocol is up

Hardware is Gt96k FE, address is 0017.5abb.8ffe (bia 0017.5abb.8ffe)

Description: "X"

MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation 802.1Q Virtual LAN, Vlan ID 1., loopback not set

Keepalive set (10 sec)

Full-duplex, 10Mb/s, 100BaseTX/FX

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters 06:52:17

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 3000 bits/sec, 5 packets/sec

5 minute output rate 1000 bits/sec, 2 packets/sec

93624 packets input, 6378502 bytes

Received 81579 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

14823 packets output, 1376643 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

Counters looks fine, and the config is similar to other sites, Full-Duplex/10. No way to change to Full-Duplex/100 because of the device facing us. But this config works good in other remote sites.

Thx

[wochanda]

What do you mean "try to access a router via metroethernet"? You mean a remote telnet connection is slow?

How is the performance of the network behind the 2800? Are you able to push/pull files to hosts behind the router?

If so, it doesn't sound like a MetroE problem. Could be that your router is too busy doing other things to respond to your telnet. To check, try a 'show proc cpu history'.

[enriquebs]

Yes, it's an ssh session to a 2800 router via MetroLAN. I don't manage the LAN, so, I can't get access to any host.

Anyway, the router cpu never goes over 5%

thx

[sundar.palaniappan]

Hi,

The slowness may be due to the default MTU setting. Equipment or links on the SP network may have a problem with an MTU 1500 + trunk overhead. Can you configure the command 'ip tcp adjust-mss 1400' on the interface facing the users (LAN) and see it that makes any difference.

HTH

Sundar

[enriquebs]

HI Sundar,

I wanna try it, but there is something that I don't understand... when you says "command 'ip tcp adjust-mss 1400' on the interface facing the users (LAN)" do you mean the interface on the 2800 router facing the MetroEthernet network? because the LAN addresses are not managed bu us...

thx

[sundar.palaniappan]

Hi,

Actually, you can configure the command 'ip tcp adjust-mss 1400' on any interface in the path of the TCP traffic. What this does is the router transparently lowers the MTU to 1400 during the TCP session negotiation between the client and the server. I have had good success eliminating MTU problems when doing so.

Good Luck!!

HTH

Sundar