Solved: Help with Cisco 871-K9 - Page 2

martinsajon · ‎09-09-2009

Hi everyone! I'm having trouble with my 871 router.

My problem is the next one.

It's starts like this:

My ISP give me an address by DHCP, it is connected to a 1841 (Fe 0/1), on Fe0/0 I assign 10.22.1.1 and by DHCP on my 871, I gather the IP the router gives me.

Now, in the 871, as you can see on the attach everything's configured, I can make pings to everything unless to my computer, with the IP 10.22.2.3 and Gateway 10.22.2.1 (Vlan1). Therefore, I ping from my computer to the vlan1 (inside) and the Fe4 port (outside) -works- but I dont have access to the web. Neither I can ping 10.22.1.2 that is 1841 router.

Any ideas of what I'm doing wrong?

1841 is working perfect and it's natting the public ip into private.

Jerry Ye · ‎09-09-2009

No, it can be on access port if you just want to support a single subnet. I don't think the 871 will support more than 2 VLAN's.

Regards,

jerry

martinsajon · ‎09-10-2009

Jerry, everythings working but I'm having a very slow connection with the 871, am I missing any command?

I'm connected directly with another computer to the 1841, and it's working normally.

Jerry Ye · ‎09-10-2009

Can you check your CPU on the 871 which process is using lots of CPU cycle?

show proc cpu

Also, how many PC is behind the 871?

Also can you remove this command on interface F4

ip flow ingress

This is for netflow, and I don't see you have any netflow collector configured.

Please keep in mind that 871 is a low end router, and the performance is much lower than the 1800 series.

HTH,

jerry

martinsajon · ‎09-10-2009

Jerry, I attach you the results, I've just removed the ip flow ingress command.

And I'm only using one computer at this time, I know 871 has a lower performance, but the web pages take too long to open, and I can't even open messenger.

martinsajon · ‎09-10-2009

For your consideration, now I'm downloading a Excel file, and the transfer rate is about of 1.2KB/sec, meanwhile, here in my laptop is about 412KB/sec

Jerry Ye · ‎09-10-2009

Your CPU process looks fine. Could you please do the following commands

no service tcp-keepalives-in

no service tcp-keepalives-out

no ip reflexive-list timeout 120

no ip ssh source-interface FastEthernet0

no logging source-interface FastEthernet0

Troubleshooting latency is pretty complicated. There might be lots of TCP re-transmission happening in the network. You can check this with a sniffer to see what is happening on the network.

HTH,

jerry

martinsajon · ‎09-10-2009

Jerry, those commands helped a bit. So if theres lots of TCP re-transmission, what would I have to do? I'm watching with Wireshark and seems that there is a lot of re-transmissioning.

I would have to use: ip tcp adjust-mss xxx?

Regards!

Jerry Ye · ‎09-10-2009

I would find out the what cause the re-transmission first. Adjusting TCP MTU will fix fragmentation problem. I would like to see the interface status along the path first. I am trying to look for errors along the path to rule out any physical problems.

The output I am interested is from show interface fx/x command

R1#sh int f0/0

FastEthernet0/0 is up, line protocol is up

... SNIP ...

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

... SNIP ...

210469 packets input, 20392024 bytes

Received 210311 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

302463 packets output, 25408663 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 unknown protocol drops

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

R1#

Regards,

jerry

martinsajon · ‎09-10-2009

Jerry, the show int of the 871 is the next one:

Kepler#sh int fast 4

FastEthernet4 is up, line protocol is up

Hardware is PQUICC_FEC, address is 001c.f68c.d6af (bia 001c.f68c.d6af)

Description: (outside) InterNet uplink

Internet address is 10.22.1.25/24

MTU 1500 bytes, BW 100000 Kbit/sec, 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 00:00:19, output 00:00:09, output hang never

Last clearing of "show interface" counters never

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 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

12780 packets input, 12752825 bytes

Received 768 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

7481 packets output, 1323110 bytes, 0 underruns

0 output errors, 0 collisions, 1 interface resets

0 unknown protocol drops

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

Kepler#sh int vlan1

Vlan1 is up, line protocol is up

Hardware is EtherSVI, address is 001c.f68c.d6a5 (bia 001c.f68c.d6a5)

Internet address is 10.22.2.1/29

MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,

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

Encapsulation ARPA, loopback not set

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

Last input 00:00:04, output never, output hang never

Last clearing of "show interface" counters never

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 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

9016 packets input, 1718675 bytes, 0 no buffer

Received 12 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

12164 packets output, 12687233 bytes, 0 underruns

0 output errors, 1 interface resets

0 unknown protocol drops

Jerry Ye · ‎09-10-2009

This one looks pretty clean. Can you do the show interface on the port your PC is connected to?

If you can do that on the 1841, that would be great.

Regards,

jerry

martinsajon · ‎09-10-2009

Show int, from my pc is connected to.

Kepler#sh int f1

FastEthernet1 is up, line protocol is up

Hardware is Fast Ethernet, address is 001c.f68c.d6a6 (bia 001c.f68c.d6a6)

MTU 1500 bytes, BW 100000 Kbit/sec, 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

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

Last input never, output never, output hang never

Last clearing of "show interface" counters never

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 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

9250 packets input, 1794276 bytes, 0 no buffer

Received 39 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 input packets with dribble condition detected

17022 packets output, 13084979 bytes, 0 underruns

0 output errors, 0 collisions, 2 interface resets

0 unknown protocol drops

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier

martinsajon · ‎09-10-2009

The show int of the 1841 is the following:

FastEthernet0/0 is up, line protocol is up

Hardware is Gt96k FE, address is 001b.53f9.063e (bia 001b.53f9.063e)

Description: (outside) InterNet uplink

Internet address is 186.136.51.14/24

MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,

reliability 255/255, txload 1/255, rxload 6/255

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 00:00:02, output 00:00:00, output hang never

Last clearing of "show interface" counters never

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 2383000 bits/sec, 216 packets/sec

5 minute output rate 75000 bits/sec, 131 packets/sec

2448100 packets input, 3040226785 bytes

Received 48030 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

1588140 packets output, 171645278 bytes, 0 underruns

0 output errors, 0 collisions, 2 interface resets

0 unknown protocol drops

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

Jerry Ye · ‎09-10-2009

Okay, all your interfaces are clean.

How does the network behave during none peak hour?

Regards,

jerry

martinsajon · ‎09-10-2009

Yep, I dunno what is happening, during peak hour it slows down, but in that pc I cannot enter to messenger, and web pages load very slow.

Now, in my laptop I'm downloading at 300KB/sec and in the computer connected to the 871 the speed is 3KB/sec. WEIRD

Regards!

Thanks you very much for your help!

Jerry Ye · ‎09-10-2009

It looks like your link is very congested during peak hour.

Regards,

jerry