1 Copper

bridging vlans

I am new to dell after 40 years of cisco and I am in need of assistance to get around a temporary but immediate problem.  We are moving away from Nexus 7Ks/3850's to Dell 9100z/5048.   

Right now we have a "server" vlan, (vlan1, , defined on the 7K's.  There is a port channel between the 7Ks and the Dell equipment. The dells were configured by a consulting team long since gone.  They mainly used default set ups, one of which is to leave vlan1 as the default vlan so there is no vlan1 in the 'new world'.

Originally we were going to migrate servers from the old world to VMS in the new world, and give them new IP addresses.  So we defined a new subnet and vlan, in this case vlan and vlan 2.  The Nexus 7Ks' carry the SVI that is the default gateway for the network, and the Dells carry the SVIs that is the gateway for the network.  We have a static route on the 7Ks to point to the Dell SVI for network and a static route on the Dells to point to the Nexus SVI for nework   Traffic to/from devices in each network flows over the port channel between Dell/Cisco using those static routes and life is good.

Enter changes.  A decision was made to NOT convert the servers from the old IP range to the new range.  This is because there are a number of references to those servers by their current IP in various applications.  The right and wrong is not up for debate, it is what it is.  I just need to 'bridge the gap'.

So here's my issue.  We can no longer route because will now be on both sides of the Dell/Nexus connection.  So layer 2 bridging seems to be my only options.  But with the Dells the default vlan is 1 so I can't create an SVI or put ports in vlan 1.

These articles, while not referring to the same equipment, would seem to apply:



But they don't address the potential fall out or what I should do to contain/prepare for that fall out.


Another possible solution would be if I could have the same subnet be in two different vlans (vlan1 on Nexus and a new...vlan 3 for example... on Dell).  This has the advantage of allowing us to move away from using vlan1 altogether...a best practice according to security teams.  But how would I forward that traffic? 

In the brocade world it is possible to configure a command on the vlan interface "ip follow ve x".  You address vlan x with your default gateway.  Devices in other vlans could point to that IP for their gateway.   The SVI for their vlan simply says to "follow the pathway outlined by vlan x".     Is there a similar command in Dell World?

I am fully open to any and all suggestions for getting out of Dodge.  I just need to get, in vlan 1 on the Cisco side, to in vlan-whatever on the Dell side.


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