VLANs Missing when passing trhough 2 switches...

CiscoSlicster · ‎09-05-2013

Hello,

Maybe someone can help me figure out the issue I'm having? We have 2 x 3750 switches stacked, one of which is our Default-Gateway or what we call the CORE(SwitchA) and the other is just a stack(SwitchB) without routing that is connected with a Trunk/Etherchannel to the CORE. We have 3 of our 6 VLANs passing though the Trunk to SwitchB which works fine but attached to SwitchB are some Cisco BladeCenter switches in "Client-Mode". The BladeCenterSwitch does not receive the 3 VLANs from SwitchA even though SwitchB has them however, all the VLANs configured on SwitchB do seem to be available. I've provided a disagram of the configuration and attached the configurations. Hopefully someone can help me out because I'm stuck. Thanks.

Partha Dasgupta · ‎09-05-2013

Hi,

can we run the following command in swich B

- no ip routing

-no system mtu routing 1500

and verify

Regards

Partha

CiscoSlicster · ‎09-05-2013

I had already ran "no ip routing" on SwitchB as you'll see in the configuration files I provided, there is no "ip routing". As for the "no system mtu routing 1500", I ran it but when I do a "show run" it still shows up.

Partha Dasgupta · ‎09-05-2013

1. Are we able to reach SVI ip address of Vlan 11 and 116 of switch A from Switch B.

2. If step 1 is yes, are we able to get the arp enteries of the SVI ip address of switch A in the Blade Server when we try to ping them.

3. If Step 1 is no, are we able to get the arp enteries for SVI ip address of Switch A in Switch B.

Regards

Partha

CiscoSlicster · ‎09-05-2013

I am able to reach the SVI ip addresses of SwitchA from SwitchB and I do see the arp entries of the SVI entries on SwitchB although they show up as VLAN116 when 172.19.1.0/24 is supposed to be VLAN11. The BladeCenterSwitch doesn't see any of the ARP entries except for 172.16.1.30 but it is able to ping any of them.

Switch B

Sending 5, 100-byte ICMP Echos to 192.168.116.21, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/8 ms

Protocol Address Age (min) Hardware Addr Type Interface

Internet 192.168.116.21 143 0027.0c90.6944 ARPA Vlan116

Internet 192.168.116.22 - 04fe.7f75.96c3 ARPA Vlan116

Internet 172.16.0.152 216 001a.64de.1484 ARPA Vlan1

Internet 172.19.1.254 16 0027.0c90.6944 ARPA Vlan116**supposed to be VLAN11

Internet 172.16.3.249 186 0027.0c90.6940 ARPA Vlan1

Internet 172.16.3.236 19 0027.0c90.6940 ARPA Vlan1

Internet 172.16.213.28 - 04fe.7f75.96c0 ARPA Vlan1

Internet 172.16.5.54 0 2892.4a23.3e17 ARPA Vlan1

Internet 192.168.1.254 - 04fe.7f75.96c1 ARPA Vlan40

Internet 172.19.1.1 17 0027.0c90.6944 ARPA Vlan116**supposed to be VLAN11

Internet 172.16.0.120 134 0021.5e43.524c ARPA Vlan1

Internet 172.16.1.112 0 000c.29ba.d8ef ARPA Vlan1

Internet 172.16.0.100 - 04fe.7f75.96c0 ARPA Vlan1

Internet 172.16.1.100 0 0050.5688.452c ARPA Vlan1

BladeCenterSwitch

Sending 5, 100-byte ICMP Echos to 172.19.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/9 ms

Protocol Address Age (min) Hardware Addr Type Interface

Internet 172.16.0.152 - 0024.c341.39b7 ARPA FastEthernet0

Internet 127.0.20.20 - 0000.0000.0000 ARPA Virtual1

Internet 172.16.5.54 106 001a.64de.1485 ARPA FastEthernet0

Internet 192.168.1.253 - 0024.c341.39c1 ARPA Vlan40**this VLAN is from SwitchB and is seen

Internet 172.16.1.30 212 001a.64de.1485 ARPA FastEthernet0

Internet 172.16.1.112 212 001a.64de.1485 ARPA FastEthernet0

Internet 172.16.1.100 213 001a.64de.1485 ARPA FastEthernet0

Partha Dasgupta · ‎09-05-2013

It looks like vlan information is getting correclty progagate in arp table.

1. Verify if the arp table in switch A is displaying the correct vlan against the ip address.

2. Clear the arp table and verify whether we are relearning the arp information correclty . If yes , verify the status

3. If step 1 fails we try to reload the switch B if possible and verify

Regards

Partha

-

Partha Dasgupta · ‎09-05-2013

correction:

It looks like vlan information is not getting correclty progagated in arp table of switch B

1. Verify if the arp table in switch A is displaying the correct vlan against the ip address.

2. Clear the arp table and verify whether we are relearning the arp information correclty . If yes , verify the status

3. If step 1 fails we try to reload the switch B if possible and verify

Regards

Partha

CiscoSlicster · ‎09-05-2013

1. I do see all the arp entries with the correct VLANs on SwitchA

2. I cleared the arp and here is what I see now, they are all correct but I don't see any from VLAN 11 now.

Protocol Address Age (min) Hardware Addr Type Interface

Internet 192.168.116.21 1 0027.0c90.6944 ARPA Vlan116

Internet 192.168.116.22 - 04fe.7f75.96c3 ARPA Vlan116

Internet 172.16.213.28 - 04fe.7f75.96c0 ARPA Vlan1

Internet 172.16.5.54 0 2892.4a23.3e17 ARPA Vlan1

Internet 192.168.1.254 - 04fe.7f75.96c1 ARPA Vlan40

Internet 172.16.1.112 0 000c.29ba.d8ef ARPA Vlan1

Internet 172.16.0.100 - 04fe.7f75.96c0 ARPA Vlan1

Internet 172.16.1.100 0 0050.5688.452c ARPA Vlan1

CiscoSlicster · ‎09-05-2013

I just did another test...

On SwitchB, I added "int vlan 11" with an ip of 172.19.1.252

On BladeCenterSwitch, I added "int vlan 11" with an ip of 172.19.1.253

From SwitchB, I can ping anything in VLAN11 except for 172.19.1.253

From BladeCenterSwitch, I can ping anything in VLAN11 including 172.19.1.252 but cannot ping itself(172.19.1.253)

Partha Dasgupta · ‎09-05-2013

1. Try to ping vlan 11 SVI ip of switch A from Switch B and verify what is the arp enteries status ?

2. Are we able to get vlan 116 SVI ip from Blade server

Regards

Partha

CiscoSlicster · ‎09-05-2013

1. Works and ARP entry shows up correct with VLAN11

2. Ping works

Partha Dasgupta · ‎09-06-2013

hi ,

r we still facing the issue?

Peter Koltl · ‎09-08-2013

Use VTP or create the VLANs in bladecenter switch. The command is

vlan 11

name Voice

etc.

CiscoSlicster · ‎09-09-2013

I ended up going through the entire configuration of each switch. I cleaned up all the old invalid configuration, setup all BladeCenter switches to be identical and then retried passing the VLANs. At first it didn't seem to work because whenever I added a IP to a VLAN interface on a BladeCenter switch, I was unable to reach the device but when I tried adding the VLAN to a VMWARE host that was connected to a BladeCenter switch it worked. I looked up the settings on my IBM BladeCenter Management at it turns out that I had to ENABLED the option "External management over all ports". In other words, the VLANs may have been working this whole time except that I was never able to get any of the VLAN interfaces to work from the BladeCenter switches because of the Management option that was DISABLED. Anyhow it was a weird one but it's fixed now and it gave me a reason to do an overhaul/cleanup of my configurations.

Thanks for your help.