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CISCO SWITCHES FOR SMALL and MEDIUM BUSINESS

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Beginner

SG500X-48 DHCP issue

I created 4 VLAN on SG500X-48 switch, with default VLAN 1 disabled.
(AD, DHCP & DNS server IP = 192.168.11.88, Default Gateway IP = 192.168.11.1)

DHCP server has scoops for VLAN 11, VLAN 21, VLAN 31 & VLAN 41

VLAN 11 - new default VLAN for AD, DHCP & DNS server (192.168.11.0/24)
VLAN 21 - Voice-VLAN (192.168.21.0/24)
VLAN 31 - Prod-VLAN (192.168.31.0/24)
VLAN 41 - Dev-LVAN (192.168.41.0/24)

VLAN 21, 31 & 41 cannot obtain auto IP addresses from VLAN 11's DHCP server

I have enabled ip helper-address 192.168.11.88 255.255.255.255 on each VLAN, but "show run" command results "ip helper-address 192.168.11.88 255.255.255.255 37 42 49 53 137 138"

If I added port 67 & 68 to the end of the "ip helper-address ip helper-address 192.168.11.88 255.255.255.255 67 68", it returns the following error "Ports 67-68 are reserved for BOOTP/DHCP"

If anyone can help shed some light I would really appreciate it.

Thanks in advance.

1 ACCEPTED SOLUTION

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Participant

The Cisco SMB switches operate differently.

The IP Helper command on these units is just for UDP forwarding of odd services.

There are dedicated commands for DHCP relay:

ip dhcp relay address XXX.XX.XX.XX
ip dhcp relay enable
ip dhcp information option
ipv6 dhcp relay destination XXXX:XXX:XXXX:XX:XX

 

Then, on each SVI, you enable DHCP Relay as needed (you do not enable DHCP relay on the SVI directly connected to the DHCP server):

interface vlan XX
 ip dhcp relay enable
 ipv6 dhcp relay destination

View solution in original post

3 REPLIES 3
Highlighted

Some things to check, and I don't mean to offend if some of them seem obvious but you didn't list it above.

  • Is the switch in L3 mode?
  • Did you create SVIs for each of the VLANs?
Highlighted
Participant

The Cisco SMB switches operate differently.

The IP Helper command on these units is just for UDP forwarding of odd services.

There are dedicated commands for DHCP relay:

ip dhcp relay address XXX.XX.XX.XX
ip dhcp relay enable
ip dhcp information option
ipv6 dhcp relay destination XXXX:XXX:XXXX:XX:XX

 

Then, on each SVI, you enable DHCP Relay as needed (you do not enable DHCP relay on the SVI directly connected to the DHCP server):

interface vlan XX
 ip dhcp relay enable
 ipv6 dhcp relay destination

View solution in original post

Highlighted

What will be the command for ipv4 addresses? Shall I just replace ipv6 with ipv4 on these commands?