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New Member

PXE/RIS/Cisco

all - any help would be appreciated..

i have a RIS/DHCP server on subnet 10.1.0.0 255.255.254.0

Switch A (5000)=10.1.0.2 PXE Client are able to obtain DHCP from Server

Switch B (4006)=10.1.0.3 PXE Client UNABLE to obtain DHCP from server

switch A connects to Router and switch B connects to switch A. the subnet mask is 255.255.254.0... all ports on VLAN 1

Server sits on switch A

thoughts?

6 REPLIES
Cisco Employee

Re: PXE/RIS/Cisco

Do you have the "set port host x/y" configured on the switch ports of CAT4006? If you have, try capturing a sniffer trace and see what's going on. To decode the trace, the following page should help

http://www.cisco.com/warp/public/473/100.html

New Member

Re: PXE/RIS/Cisco

No, I have not used that command.. should I?

New Member

Re: PXE/RIS/Cisco

that command set port fast on the port - port fast was already configured... anything else?

Cisco Employee

Re: PXE/RIS/Cisco

Yes you should. It's a macro command. It enables port-fast, disables channelling and trunking

http://www.cisco.com/warp/public/473/12.html

http://cio.cisco.com/univercd/cc/td/doc/product/lan/cat4000/rel6_3/cmd_ref/set_l_q.htm#31406

Enable set port host only on ports connected to a single host. Connecting hubs, concentrators, switches, and bridges to a fast start port can cause

temporary spanning tree loops.

New Member

Re: PXE/RIS/Cisco

So, once I do this for each individual port it's then able to obtain an address... why would this command as opposed to "set spantree portfast mod/port enable"?

Cisco Employee

Re: PXE/RIS/Cisco

Excellent!. As I mentioned earlier, this command is a macro. In addition to enabling portfast, it also disables channeling/trunking which disables channelling and trunking negotiation. Four main features that cause the delay for the switch to begin servicing a newly connected workstation are

1)Spanning-Tree Protocol (STP)

2)EtherChannel negotiation

3)Trunking negotiation

4)Link speed/duplex negotiation between the switch and the workstation

We can take care of first 3 with set port host command

Hope this answers your question

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