HP 4208vl routing within the default VLAN


we haven't any free IP v4 adresses in our private class C subnet.

So we need a second subnet.

Our HP 4208vl Switch should routing between theses subnets.

According to the 4208 Quickspecs the HP switch automatically routes between VLANs.

But can the 4208vl routing with within the default VLAN ?

Thank you,
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Zephyr ICTCloud ArchitectCommented:
If you are asking if it is possible to set routing between the default VLAN (VLAN1) and other VLANs, then yes you can set that up without a problem.

Just enable "ip routing".

ip routing enable

Open in new window

Don't forget to set an ip on the second VLAN
tutschi69Author Commented:
No we don't want a second vlan.

Is it possible in the default vlan ? Two IP-addresses / subnets on the switch ?
Zephyr ICTCloud ArchitectCommented:
Why don't you just make your range bigger?

eg: if you now have (, change it to ( which provides 254 more addresses or ( to get even more ...

This way no routing is needed, just change the subnetmask of all the devices connected to the network.
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Craig BeckCommented:
I wouldn't advise adding a different subnet to the same VLAN.  Technically it is possible and should 'work' but really it will just give you unnecessary headaches with DHCP and routing (if nothing else).

Spravtek gives good advice, although the example is a bit flaky :-)

If you have you 'can' expand it using a /23 network mask, however that won't give you - as you might expect.  It will give you -

Just something to be aware of as when you come to configure it the network won't look like you expect it to look.  What I mean is that the base network address would look like instead of
tutschi69Author Commented:
Hello craigbeck,
Hello spravtek,

thank you for your advice and hints :)

New subnetmask /23:
If I change the subnetmask, it is the same job, as to change the IP Adresses to Because I had to change all devices (routers, firewall, server, switche, statics client, access points, time clocks ...).

New VLAN with new DHCP Scope:
If I create a new VLAN with a new subnet, routed via HP 4208vl, I have to look to which port the client is connected. Unfortunately we have no numbers on our patch pannel. So if a static client (or ap, server, time clock...) is connected to the new vlan, the client gets no communication :-/

No new vlan with routing:
My favorit is a single vlan with routing :-) But how can I active the routing feature in the 4208vl and a second IP Adress in a different subnet ?

Thank you,
Craig BeckCommented:
If you change the mask it's not exactly the same as changing the IP addresses.  It's a little less work but still tedious.

Your preferred method is what I'd call 'dirty'.  It should work in theory and it will do what you want.  But, it will also give you some unnecessary headaches.  For example, when a client tries to obtain an IP address via DHCP it's 50/50 as to which IP range the client would obtain an IP address from.  If you don't use DHCP it's fine though.

Also, if clients want to talk to clients on the other subnet, they have to put their traffic via the HP router.  That's not really what you want and just puts unnecessary overhead on the router and consumes bandwidth on the link to it.  This will be a bottleneck if you have lots of clients pushing lots of data.

My advice is really to expand the range and adjust the subnet mask on your existing devices.
tutschi69Author Commented:
Hello craigbeck,

we make a new dhcp scope. The old one will be expire and disabled.

No client will be talk to other clients. And if they all on the same new ip subnet, it doesn't matter :)

So my question form the first post again :-)
How to configure the HP 4208vl for routing within the default VLAN ? And a second IP adress on the same vlan.

Thank you
Craig BeckCommented:
If you make a new DHCP scope and disable the old one, you're just moving everyone to a new range, therefore it makes more sense to just change the subnet mask on the interface and let the clients get their new subnet mask from DHCP.  No routing needed.

If you add a second IP on the VLAN it 'should' allow you to route between the subnets - but as I said before this is pointless.

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tutschi69Author Commented:
OK I' try it next Weekend:

- show IP
- configure
- vlan 1
- ip adress
- ip routing
- write Memory

tutschi69Author Commented:
I've requested that this question be closed as follows:

Accepted answer: 0 points for tutschi69's comment #a39458204
Assisted answer: 250 points for craigbeck's comment #a39455014
Assisted answer: 250 points for craigbeck's comment #a39455078

for the following reason:

It worked in one VLAN :-)
tutschi69Author Commented:
It worked in one vlan !
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