VLAN Trunking/Tagging issue

[Roberto_CC]

Hello, I'm trying to extend our Default VLAN1 to a switch chassis that is three physical switches away. I'm established tagging with VLAN100 as the pathway between the two remote switches. The setup is this:

<[ProCurve5308xl] - Default VLAN 1, untagged Port H1>-connects to-<VLAN 100, untagged Port47- [ProCurve2910] - VLAN 100 tagged Port48>-connects to-<VLAN 100 tagged Port 48 - [ProCurve2910] - VLAN 100 untagged Port 17>-connects to-<Default VLAN1 untagged Port 1 [ProCurve 3800] All 26 ports on this switch untagged on Default VLAN1>

With this configuration in place, I would expect any host plugged into the untagged VLAN1 ports on the 3800 to behave as though they were connected to any untagged VLAN1 ports on the 5308xl. When happens however, is that I cannot ping other devices on the VLAN1 subnet, nor can I draw DCHP from my VLAN 1 router directly connected to the 5308.

Thank you in advance for any help with this!

Roberto

[paulgear]

Hi Roberto,

I think i understand what you're trying to do (i.e. use VLAN 100 as a tunnel connecting VLAN 1 on other switches), but i urge you not to do this.  If you don't keep all of your VLAN numbers consistent in a set of switches sharing the same L2 domain, it will come back to bite you later.  Is there a particular reason you don't want VLAN 1 present on the 2910 switches that you're trying to pipe it through?

[Roberto_CC]

Hi Paul, thanks very much for your time and help with this.

VLAN 1 on the other switches is currently in production as the L2 domain of our DMZ. We have a point to point link from the office to our data center on port 48 of the 2910s that I trunk over, but VLAN1 is already in service on both switches, hence the need for something like VLAN100 to span the switches and recreate the default VLAN1 characteristics on the far side switch.

Any suggestions or advice would be appreciated.

Roberto

[paulgear]

Hi Roberto,

My suggestion is to use VLAN 100 throughout for this VLAN. Then you can turn on GVRP and the switches will take care of making sure each VLAN ends up in the right place.

[Roberto_CC]

Hi Paul, thank you for your help with this. I may take your initial advice and reconfigure the VLANs in a more coherent manner, making VLAN1 consistent throughout. I'd rather put in the extra work now to create a more stable long term design.

Thanks again,

Roberto