04-14-2009 04:59 AM - edited 03-06-2019 05:09 AM
Hi,
I am connecting Cat 3550 EMI (SW1) to Cat 3550 SMI (SW2).
The cable connection is as follows:
1- Sw1 to Patch Panel 1 (Straight)
2- Patch Panel 1 to Patch Panel 2 (Straight)
3- Patch Panel 2 to Sw 2 (Cross over)
The ports are configured as:
!
interface FastEthernet0/21
description JCITYSW02 trunk connection
switchport trunk encapsulation dot1q
switchport mode trunk
no ip address
end
Global commands:
spanning-tree mode pvst
spanning-tree extend system-id
Problem is switches are not able to see each other.
What am I missing?
Please help.
Thanks,
Asif.
04-14-2009 06:25 AM
Hello Asif,
In theory your setup looks OK.
Have you tried putting a direct (x-over) cable between the two switches?
Have you tried using a different patch panel interlink?
What does sh int fa0/21 show? ie is it down/down?
Regards
04-14-2009 06:38 AM
No, I did not try putting a direct x-over cable between two switches neither different patch panel interlink.
The output of sh int fa 0/21 shows:
FastEthernet0/21 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 000d.28fd.4315 (bia 000d.28fd.4315)
Description: JERCITYSW02 trunk connection
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
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, 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 0 bits/sec, 0 packets/sec
5 minute ouxtput rate 0 bits/sec, 0 packets/sec
214205 packets input, 30044425 bytes, 0 no buffer
Received 48145 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 40525 multicast, 0 pause input
0 input packets with dribble condition detected
2148548 packets output, 500501024 bytes, 0 underruns
0 output errors, 0 collisions, 11 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
04-14-2009 06:39 AM
Are you saying you do not see the partner switch layer 2 mac address when you issue "show mac address-table" or that they cannot see one another at layer 3 IP address?
04-14-2009 07:04 AM
Hi,
Your ports are showing up/up. Therefore the switches are connected together OK on a physical layer.
What exactly is the problem?
What does "sh cdp nei" tell you?
Regards
04-14-2009 07:55 AM
Sh Cdp nei does not show the neighboring switch. Sw1 does not Sw2 and vice versa.
04-14-2009 07:54 AM
I did not check mac table, but I cant ping from one switch to other. The show cdp nei on both switch does not show any entry for other.
04-14-2009 08:01 AM
I would prefer to use show mac address-table over show cdp neighbor because we do not know that cdp is running (is by default) or that it has not been disabled on a given port.
Having said that can you please show us the output from each switch given the following command:
"show run int vlan 1"
04-14-2009 08:55 AM
Here is the output:
Sw1:
Building configuration...
Current configuration : 91 bytes
!
interface Vlan1
ip address 192.168.10.1 255.255.255.0
ip helper-address 10.1.10.5
end
SW2:
Current configuration : 91 bytes
!
interface Vlan1
ip address 192.168.10.12 255.255.255.0
ip helper-address 10.1.10.5
end
04-14-2009 09:00 AM
Asif,
SW1:
(conf)#cdp run
SW2:
(conf)#cdp run
I just want to know which one of them is responsible to be a gateway of VLAN1. Are they running as Layer3 switch?
Toshi
04-14-2009 09:04 AM
CDP is running as I can see other cisco devices when I do sh cdp nei.
SW1 is the gateway of vlan1.
04-14-2009 09:11 AM
Asif,
First of all if the switch1 is responsible to be a gateway of vlan1. At switch2 I would take an ip-helper command off. Please post the configuration of both interfaces from both switches.
Can you use a "show cdp ne" command on both switched and see other switches but these two?
Toshi
04-14-2009 09:38 AM
Yes, I can use cdp neighbor but cant see the SW1 from SW2 and vice versa. However, I can see all other cisco devices connected to SW1 or SW2.
I am not on site right now, will post interface config later.
Thanks
04-14-2009 11:18 AM
1- Sw1 to Patch Panel 1 (Straight)
2- Patch Panel 1 to Patch Panel 2 (Straight)
3- Patch Panel 2 to Sw 2 (Cross over)
Either use 'Straight-through Cabling' to the patch panel on both switches' uplinks or use 'Crossover Cabling' on both.
I haven't seen this type of cabling implemented before and I'm not sure if it's going to work.
With today's auto-mdix implementation, I see 'Straight-through Cabling' implemented across the board.
__
Edison.
04-15-2009 04:34 AM
Edison,
Thanks for your suggestion. I tried with Straight through cabling first, but connection did not come up. Then I tried with one side of crossover, which was able to bring the connection up for some time. Then it went down.
I think its more of a physical cabling issue, if my configuration is correct. Can you please check the config and let me know if I have any problems there.
Thanks,
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