SG500 dhcp relay for two different dhcp servers

[ANT2CISCO]

Hi there.

I have Cisco SG500 in L3 mode.

Now I need to get ip addresses for vlans from two different external dhcp servers (for ex. 192.168.1.21 and 10.17.10.10).

For Cisco Catalyst it would looks something like this:

int vlan 100

   ip addr 10.100.10.1 255.255.255.0

   ip helper-addr 192.168.1.21

int vlan 110

   ip addr 10.150.20.1 255.255.255.0

   ip helper-addr 10.17.10.10

int vlan 120

   ip addr 10.200.20.1 255.255.255.0

   ip helper-addr 10.17.10.10

etc

....

Anyway to get this construction on SG500?

Thx

[mipopov]

Hello,

You can try something like this:

for the example given (vlan 100):

switchxxxxxx(config)# ip helper-address 10.100.10.1 192.168.1.21

for the example given (vlan 110):

switchxxxxxx(config)# ip helper-address 10.150.20.1 10.17.10.10

for the example given (vlan 120):

switchxxxxxx(config)# ip helper-address 10.200.20.1 10.17.10.10

Cheers,
Mike

[ANT2CISCO]

Hi, Mike 
Thank you for your reply.

Would you clarify, do I have to keep global ip dhcp relay settings?
when I've used one external dhcp server, I've configured:
ip dhcp relay enable
ip dhcp relay address 192.168.1.21
+
ip dhcp relay enable
on interface vlan xxx,
and it works fine. But I have to add one more dhcp-server right now.

Just I've added
ip-helper address 10.150.20.1 10.17.10.10, but it didn't work: /

[mipopov · Accepted solution]

Hi again,

You can try with relay again. Remove the helper command and go to vlan interface (10.150.20.1):

switchxxxxxx# config
switchxxxxxx(config)# interface vlan 30
switchxxxxxx(config-if)# ip dhcp relay enable
switchxxxxxx(config-if)# ip dhcp relay address 10.17.10.10

*Note: 

The operational status of DHCP Relay on an interface is active if one of the following conditions exist:
• DHCP Relay is globally enabled, and there is an IP address defined on the interface.
Or
• DHCP Relay is globally enabled, there is no IP address defined on the interface, the interface is a VLAN, and option 82 is enabled.

Up to 8 servers can be defined.

I'm adding you a link to CLI guide just in case:

http://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbms/Sx500/cli_guide/CLI_500.pdf

Hope it helps

Cheers,

Mike

[ANT2CISCO]

Hi, Mike.

Thank you for your help, it's really worked now. 

BTW, there is hidden command 'ip dhcp relay address xx.xx.xx.xx' on vlan interface.

When I've added the command, I saw there were two ip dhcp relay servers in the general configuration:

ip dhcp relay address 10.17.10.10.
ip dhcp relay address 192.168.1.21
ip dhcp relay enable

But there aren't appear any additional commands on the vlan interface:

interface vlan 150
 ip address 10.150.20.1 255.255.255.0
 ip dhcp relay enable

SG500, SW ver.1.4.9.4