PXE Booting Through a Router

[daniel.bowen]

Hi Everyone,

I am trying to enable PXE booting between VLAN's on a 3750 L3 switch. I have the IP Helper command configured on VLAN 1, point at the DHCP and Altri server on VLAN2, and have configured the ip forward-protocol udp command for ports 4011, 1758 and 1759. The Altris server is on VLAN2 and the client is on VLAN1.

It fails saying "could not connect on port 4011"

Has anyone ever got this working before?

Many thanks,

Daniel

[alex.walker]

I've had this working before. You shouldn't need ip forward-protocol except for your DHCP forwarding.

If I remember rightly, the process is:

* Client does a DHCP request (which you forward using ip helper-address)

* DHCP server replies with a client IP address, and additional options giving the IP address of the PXE server

* Client then initiates a TFTP session to the PXE server to pick up its boot image (no ip helper needed, as this is a standard unicast UDP session)

* Boot image is then executed, and Altiris session can then kick in. I think it uses TCP 401 and 402 by default.

A few things you might want to check:

* Check your DHCP settings (default gateway, subnet mask) etc are OK. Can you ping the Altiris server from a client on VLAN1?

* See if you're picking up the boot image OK

* If you're using Altiris in Multicase mode, you'll need to turn on multicast routing on your router (PIM or similar)

Hope this helps a bit.

Alex.