topic Re: Layer3 forwarding in General Topics

Layer3 forwarding

Retired Member — Tue, 21 May 2013 13:18:46 GMT

Hi all,

Even I do not choose this function I can use layer2 vlan interface's as layer3.I could not understand what does "layer3 forwarding" function really do .Can someone explain this ?

Thanks.

Re: Layer3 forwarding

Retired Member — Tue, 09 Jul 2013 08:23:32 GMT

any update for that ?

Re: Layer3 forwarding

mikand — Tue, 09 Jul 2013 08:28:40 GMT

You mean that even if you disable l3-forwarding for a specific vlan-interface it can still route traffic?

That is the output from "show vlan all" says "disabled" regarding layer3 forwarding?

To me disabling "l3-forwarding" is the same as running "no ip routing" in a cisco l3-switch.

That is you can still ping this vlan-interface (if it has a mgmt-profile that allows ping attached to it) but if you send a packet to it with a dstip which isnt the ip of this vlaninterface then the packet should be dropped.

Re: Layer3 forwarding

Retired Member — Tue, 09 Jul 2013 08:41:19 GMT

All routing is working fine between vlans and other layer3 interfaces.

Re: Layer3 forwarding

mikand — Tue, 09 Jul 2013 08:51:37 GMT

Sounds like you should contact the tech support... and then update this thread with the result.

To me disabling l3-forwarding for a particular vlan-interface, no matter if this vlan-interface has an ip address attached to it or not, should mean that this vlan-interface wont forward packets to other vlan-interfaces and it should not accept packets from other vlan-interfaces aswell. However it should still forward packets to/from physical interfaces which are part of this vlan.

In your case ethernet1/1 should be able to forward packets to/from ethernet1/10 since both are part of vlan.10 but ethernet1/1 should not be able to forward packets to/from ethernet1/7 since that interface is part of vlan.2 which is different vlan.

Re: Layer3 forwarding

Gregoux — Wed, 10 Jul 2013 14:31:45 GMT

VLAN interface is used as a gateway for routing purpose

you create a vlan object with 2 or more interface layer2, at this broadcast domain you can bind a Vlan Interface with Layer 3 forwarding enable. that allow the machine device connecting on any port of the vlan object to used the VLAN interface ipaddress affected as the default gateway.

the vlan interface is bind to a VR that allow the routing and forward.

Re: Layer3 forwarding

Retired Member — Wed, 10 Jul 2013 21:35:27 GMT

so what happens when we do not enable forwarding ?

what is the thing that we cannot do ?

Re: Layer3 forwarding

Gregoux — Thu, 11 Jul 2013 07:04:12 GMT

so what happens when we do not enable forwarding ?

simple no forwarding,

you can create all the object VLan object and vlan interface and bind it to gather. And enable the forwarding when you need it.

regards

Re: Layer3 forwarding

Retired Member — Thu, 11 Jul 2013 07:08:08 GMT

yes but it's disable for all vlan's as you can see top

and we can do everything.vlan's can reach each other and access everywhere.

Re: Layer3 forwarding

mikand — Thu, 11 Jul 2013 08:16:19 GMT

So did you contact the tech-support yet and what was their reply?

Re: Layer3 forwarding

Gregoux — Thu, 11 Jul 2013 09:01:29 GMT

yes contact the tech support and give us the return

Re: Layer3 forwarding

Retired Member — Thu, 11 Jul 2013 12:11:02 GMT

yes I did.still open.