Inter-VLAN Routing Issue

Michael Kline · ‎04-23-2015

I have a 3750 switch with two 48-port switches connected via stacking cable. On these switches I have two VLANS: VLAN100 for data, and VLAN300 for Desktop VTCs (dVTCs). I configured the switch with VLAN 100 having an ip address.

I have verified:
-IP Routing is enabled
-the default gateway is correct
-my trunk port is dot1q encapsulated and passing VLANS 100 & 300.
-On my Cisco 2951 router, I have created sub-interfaces with IPs and dot1q encapsulation.
-I am running OSPF and verified that both my data and video networks are being advertised.

Here's the problem: When I move my dVTCs into VLAN 300, I cannot ping the devices from either the switch or the router. I am able to ping the VLAN 300 gateway from the switch, but I am not able to ping either of my dVTCs. Also, from my dVTCs, I cannot reach the gatekeeper. The interesting thing is that when I move my two dVTCs into VLAN 100 and move the VLAN 300 sub-interface address to the VLAN 100 sub-interface as a secondary address, everything works great on my dVTCs.

I have other campuses where I run the same configuration of VLANs, and everything works great. I feel like I am just missing something on my switch that I missed in my configuration but I am not seeing it. I apologize, but I am not able to post my configuration as my network is an isolated DoD network and cannot be posted. But if you have some ideas for me to check, I would appreciated it.

Reza Sharifi · ‎04-23-2015

When you move your dvtcs to vlan 300, do you see the mac addresses in that vlan?

sh mac address-table vlan 300

Also, on the router, do you see the IP address of the dvtcs?

sh ip arp <the ip address of the dvtc>

HTH

Michael Kline · ‎04-23-2015

When I move my dvtcs into vlan 300, the dvtc mac address do not show up in that vlan. Also, when I sh ip arp, I show the two dvtcs addresses in vlan 100, not vlan 300. Under the sh ip arp, I see the dvtcs gateway in vlan 300 (in this configuration, I can ping the gateway from the switch, but I cannot ping the device IPs)

When I move my dvtcs into vlan 100, both dvtc mac address do show up in vlan 100. In the sh ip arp, I show the two dvtcs and the dvctc gateway in vlan 100 ( everything works)

Reza Sharifi · ‎04-23-2015

For test, can you try creating a completely new vlan (vlan 50) and put the dvtcs in it and test again?

HTH

Michael Kline · ‎04-23-2015

I created VLAN 400 and placed the dvtcs in that vlan. When I showed the mac address table, I showed both dvtcs in VLAN 400. On the router, I created the new sub-interface for VLAN 400 and move the dvtc gateway there. When I showed the arp table, I showed the dvtc gateway in both VLAN 100 and 400 and both dvtcs were still in VLAN 100

Michael Kline · ‎04-23-2015

As a follow-up, I did a clear arp on my router and now the two dvtcs do not appear in the arp table. I do show the gateway address showing VLAN 400.

Reza Sharifi · ‎04-23-2015

I was just about to post for you to clear the arp.

So, it is working now?

Michael Kline · ‎04-23-2015

I am not able to ping the dvtcs.

I do see the gateway address showing in VLAN 400.