Article ID: 5720
Products
SecureStack C3, C2, B3
G-Series
Goals
Sample configuration
Symptoms
'ip helper-address'
Solution
One global IP Helper, configurable as in the following example, is supported with C2 firmware through 3.03.38:
C2(su)->router
C2(su)->router>enable
C2(su)->router#configure
Enter configuration commands:
C2(su)->router(Config)#ip helper-address 10.10.90.5
C2(su)->router(Config)#exit
C2(su)->router#exit
C2(su)->router>exit
C2(su)->
Multiple IP Helpers (up to three per router interface), configurable as in the following example, is supported with C3 firmware through 1.00.97, and C2 firmware 4.00.24 through 5.00.82:
C2(su)->router
C2(su)->router>enable
C2(su)->router#configure
Enter configuration commands:
C2(su)->router(Config)#interface vlan 10
C2(su)->router(Config-if(Vlan 10))#ip helper-address 10.10.90.5
C2(su)->router(Config-if(Vlan 10))#ip helper-address 10.10.90.6
C2(su)->router(Config-if(Vlan 10))#ip helper-address 10.20.93.2
C2(su)->router(Config-if(Vlan 10))#exit
C2(su)->router(Config)#exit
C2(su)->router#exit
C2(su)->router>exit
C2(su)->
Up to
six IP Helpers per router interface is supported with C3 firmware 1.01.01.0039 and higher, C2 firmware 5.01.01.0039 and higher, B3 firmware 1.01.01.0039 and higher, and all G-Series firmware.
With earlier firmware, the 'ip helper-address' command's UDP forwarding applies only to port 67 (Bootp/DHCP) traffic.
With more recent firmware, the 'ip helper-address' command's UDP forwarding minimally applies to port 67 (Bootp/DHCP) traffic but may optionally be configured to include other protocol traffic (
11980).
In all cases, a copy of eligible traffic is forwarded to all configured addresses.
See also:
5482.
