[Asterisk-Users] DHCP configuration for Cisco 7960?

[Julian Dunn]

(Apologies to those Toronto Asterisk Users' Group folks who have seen
this message... I figured I'd have more success with a wider audience)


I'm trying to boot a Cisco 7960 from an ISC DHCPD server (3.0.3 on
FreeBSD 4.11), so far unsuccessful, and getting some odd behaviour on
the wire. I wonder if anyone has done this before and therefore can
validate whether or not the traffic I am seeing is normal.

I have dhcpd.conf set up like this

---8<--- cut here ---8<---

option cisco-etherboot-server code 150 = ip-address; .
.
.
host c7960 {
        hardware ethernet 00:16:46:9B:6D:62;
        fixed-address 192.168.5.14;
        option host-name "c7960.acf.aquezada.com";
        option cisco-etherboot-server 192.168.5.7; }

---8<--- cut here ---8<---

I'm deliberately using option 150 instead of "option tftp-server"
because this is what works on the Windows end (and in any case I tried
"tftp-server" and it didn't work anyway)

On the wire what happens is this, after I power on the phone

* Bunch of CDP traffic from phone
* DHCP Discover from phone, asking for:
  - Subnet Mask
  - TFTP Server Name
  - Domain Name Server
  - Router
  - Option 150
  - ARP Cache Timeout
* DHCP Offer from DHCP server
* DHCP Request from phone
* DHCP ACK from DHCP server
* Phone does gratuitous ARP for the IP it just got
* Phone does ARP who-has for default router. No ARP response on the
wire.
* Phone does ARP who-has for DNS server. No ARP response on the wire.
* After a while, cycle starts over

The part I can't figure out is, are the last two items normal? What
would prevent the default router and DNS server from providing an ARP
reply? I should note that immediately after the phone receives its IP,
one can still not ping it.

Any ideas or suggestions?

- Julian

Julian C. Dunn, P.Eng.
Systems Administrator

e: julian.dunn at devlin.ca
p: 416-363-6316 x292
f: 416-363-6102
w: www.devlin.ca

Devlin eBusiness Architects Inc.
185 Frederick Street
Toronto, ON M5A 4L4