For When You Can't Have The Real Thing
[ start | index | login ]
start > 3Com > 4500G > Limit of 8 VLAN interfaces

Limit of 8 VLAN interfaces

Created by dave. Last edited by dave, 7 years and 352 days ago. Viewed 11,282 times. #3
[diff] [history] [edit] [rdf]
(July 11, 2007)

4500G limited to 8 VLAN interfaces

So I'm trying to pre-define a bunch of VLANs on this switch to make it as maintenance-free as possible, right? So I want to do this:

vlan 107
interface vlan-interface 107
ip address
dhcp select relay
dhcp relay server-select 1
undo shutdown

I have already defined vlans 1, and 100-106 this way. However, with the request for 107, I get:

[4500G]vlan 107
[4500G-vlan107]interface vlan-interface 107
The number of VLAN interfaces exceeded the maximum.

Which I interpret as meaning I can only handle 8 VLAN interfaces.

I can't find anything in the documentation which confirms this suspicion.

Note that I can define VLANs to my heart's content (and presumably apply them to ports). I can't create interfaces for any more than 8. Which means I can't route more than 8 directly attached networks with this router brain.

I called 3Com support (11 July 2007), and while the tech (and the senior tech on duty) agreed that there was nothing in the documentation (October 2006 as of this writing) regarding this limit, they agreed that the limit was there and there was no alternate way of doing what we wanted to do.


The tech indicated to me while I was chatting to him that this switch was, in fact, a 3Com-engineered product and not merely something 3Com had purchased and re-badged like some of their past offerings. I told him I was astounded that a 2006 product like the 4500 was limited in such a way, especially when you consider that the 4900-family of switches, which are what, six or seven years old at this point, had a limit of 32 vlans? The tech did the verbal equivalent of a shrug and commented that this switch was aimed at different applications than the 4900 was.

It is doubly astounding that such a low limit is not documented anywhere the customer (ie, me) can find it.

Personally I find it hard to recommend 3Com for anything other than edge switches these days. This isn't the first time we have been disappointed with a 3Com offering. I do know that internally we use a Cisco 3750 to do the same job that we were hoping the 4500G would do.

Hopefully this page will become obsolete rather quickly if 3Com releases an updated firmware that addresses this problem. My details for this experience are:

<4500G>display version
3Com Corporation
3Com Switch 4500G 24-Port Software Version 3Com OS V5.01.00s56
Copyright(c) 2004-2006 3Com Corporation and its licensors. All rights reserved.
3Com Switch 4500G 24-Port uptime is 0 week, 0 day, 22 hours, 33 minutes

3Com Switch 4500G 24-Port with 1 Processor 128M bytes SDRAM 16384K bytes Flash Memory

Hardware Version is REV.B CPLD Version is 006 Bootrom Version is 115 [SubSlot 0] 24GE+4SFP Hardware Version is REV.B


According to >>the downloadable specifications sheet as of 1 August 2007, the limit in the switch is only 4 ip interfaces. So apparently the switch firmware is more advanced than the marketing material.

no comments | post comment
This is a collection of techical information, much of it learned the hard way. Consider it a lab book or a /info directory. I doubt much of it will be of use to anyone else.

Useful: | Copyright 2000-2002 Matthias L. Jugel and Stephan J. Schmidt