J
J
Jan2013-12-04 10:48:37
DHCP
Jan, 2013-12-04 10:48:37

Issue with DHCP relay on Cisco SG300?

Cisco SG300-52
Firmware Version 1.3.5.58
System Mode L3
Created vlans, defined ip, assigned to interfaces, enabled global relay, enabled relay on each vlan. But the DHCP server of the address categorically does not want to issue. Judging by Wireshark, a request (DHCP Discover) comes to the DHCP server. Below is a clipping from the Cisco config. Tell me which way to dig. Thanks in advance.

v1.3.5.58 / R750_NIK_1_35_647_358
CLI v1.0
set system mode router

file SSD indicator encrypted
@
ssd-control-start
ssd config
ssd file passphrase control unrestricted
no ssd file integrity control
!
vlan database
vlan 2,101-106
exit
ip dhcp relay address 192.168.1.2
ip dhcp relay enable
bonjour interface range vlan 1
ip ssh server
!
interface vlan 1
 ip address 192.168.111.254 255.255.255.0
 no ip address dhcp
!
interface vlan 2
 name Management
 ip address 192.168.0.1 255.255.255.0
!
interface vlan 101
 name Server
 ip address 192.168.1.1 255.255.255.0
 ip dhcp relay enable
!
interface vlan 102
 name Video
 ip address 192.168.2.1 255.255.255.0
 ip dhcp relay enable

Answer the question

In order to leave comments, you need to log in

2 answer(s)
I
Ian, 2013-12-06
@Buchachalo

@zorruch The problem turned out to be banal. The DHCP server did not have a gateway specified.
And by the way, a small addition. On newer switches, ip helper-address no longer works for DHCP packets.
It is necessary like this:
1) (config)# ip dh relay enable - enable the relay globally
2) (config)# ip dh rekay addres 192.168.0.2 - specify the ip of our DHCP server
3) (config)# interface vlan 2 - enter the config interface on which we want to enable the relay.
4) (config-if)# ip dh rel en - well, enable it accordingly.
And the DHCP server does not have to be on the same subnet.

Z
zorruch, 2013-12-06
@zorruch

I think you can use this manual - www.hypercomp.ru/articles/configuring-dhcp-relay-o...
I have it configured using ip helper-address (as described in the article) and it works without problems)
example:

interface Vlan2
 description Users VLAN
 ip address 172.19.30.1 255.255.255.0
 ip helper-address 172.19.9.2
!

In the config - 172.19.9.2, DHCP server address.
Didn't write anything else.
Do not forget that the DHCP server must have a subnet from the network from which the DHCP packet comes from =)

Didn't find what you were looking for?

Ask your question

Ask a Question

731 491 924 answers to any question