Hi,
I have an SF300-24P running SW version 1.4.5.02 (latest avail) which has tree DHCP pools configured [1]. The switch is running in switch mode (L2). It has the management IP address 172.17.129.2 on VLAN 129.
I have a linux router running dhcrelay on the other VLANs, 127 and 192 and using 172.17.129.2 as server.
Any hosts attached to VLAN 129 do get an IP address, while hosts on other VLANs don't.
Dumping the traffic from the linux router on any VLAN other than where the DHCP server is (129) I can see that the DHCP relay forwards the request to the DHCP server, which, in turn, does not answer. [2]
What is weirder is that the switch does see the DHCP request and "pre-allocate" the lease [3]
Is this a known issue, or am I missing something?
Thanks!
[1]
ip dhcp server
ip dhcp pool network B_129
address low 172.17.129.51 high 172.17.129.200 255.255.255.0
time-server 193.204.114.105
dns-server 8.8.8.8
exit
ip dhcp pool network D_192
address low 192.168.192.10 high 192.168.192.254 255.255.224.0
lease 0 4
default-router 192.168.192.1
time-server 193.204.114.105
dns-server 8.8.4.4 8.8.8.8
exit
ip dhcp pool network J_127
address low 172.17.127.101 high 172.17.127.200 255.255.255.0
default-router 172.17.127.1
time-server 193.204.114.105
dns-server 8.8.4.4 8.8.8.8
exit
[2]
14:33:06.401924 IP 172.17.129.1.67 > 172.17.129.2.67: BOOTP/DHCP, Request from 78:2b:cb:d1:a3:9a, length 300
14:33:09.434442 IP 172.17.129.1.67 > 172.17.129.2.67: BOOTP/DHCP, Request from 78:2b:cb:d1:a3:9a, length 300
14:33:14.440336 ARP, Request who-has 172.17.129.2 tell 172.17.129.1, length 28
14:33:14.441197 ARP, Reply 172.17.129.2 is-at 34:db:fd:77:31:9e, length 46
14:33:32.502505 IP 172.17.129.1.67 > 172.17.129.2.67: BOOTP/DHCP, Request from 78:2b:cb:d1:a3:9a, length 300
14:33:35.560692 IP 172.17.129.1.67 > 172.17.129.2.67: BOOTP/DHCP, Request from 78:2b:cb:d1:a3:9a, length 300
[3]
lab-ah#show ip dhcp binding
DHCP server enabled.
The number of used (all types) entries is 1
The number of preallocated entries is 1
The number of allocated entries is 0
The number of expired entries is 0
The number of declined entries is 0
The number of static entries is 0
The number of dynamic entries is 1
The number of automatic entries is 0
IP address Hardware address Lease expiration Type State
---------------- ------------------ ------------------ ----------- -------
172.17.127.101 01.78.2b.cb.d1.a3. Apr 21 2016 dynamic pre-all
9a 20:41:29 ocated
