Hello,
I hope this is the right place to post questions although it concerns a 3com labeled switch...
My problem is understanding the "untagged" feature for hybrid ports and Layer-3 routing between VLAN interfaces.
I am familiar with the concepts of routing and switching and I haven't considered a Layer-3 advertised switch to be an IP router - until now. Time probably let the switches evolve and now IP routing can possibly done in hardware...
We have two networks (192.168.1.0/192.168.2.0) on the switch which are connected via a router. I figuered it should be possible to let the switch handle the interconnection instead of the slow (100Mbit/s) router.
The different subnet members are scattered across all ports...
Starting out all switch ports belong to the same VLAN (1) and its IP interface being 192.,168.1.1.
I set up an additional VLAN (2) with the IP 192.168..2.1.
Once I set the ports as untagged members of VLAN 1+2 the communication with IP clients in VLAN2 stopped working.
port -- untagged -- PVID
member
1 -- 1,2 -- 1
2 -- 1,2 -- 1
3 -- 1,2 -- 1
...
48 -- 1,2 -- 1
According to the documentation the difference between a trunk port and a hybrid port is:
"A hybrid port allows traffic of multiple VLANs to pass through untagged."
"A trunk port allows only traffic of the default VLAN to pass through untagged."
Although my ports are hybrid ports, they seem to show trunk behavior.
When I assign PVID "2" to all the ports with IP clients of the 192.168.2.0 network routing is working (the switch is the default gateway for both networks). Yet this is very tedious and unflexible - what if there's a tiny workgroup switch attached with two devices in each network?
Can someone make sense of the "untagged" feature for hybrid ports?
Any hints are greatly appreciated!
Alex