3com 8807 User Guide

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Configuring VRRP
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Enabling/Disabling the 
Function to Ping the 
Virtual IP Address
This operation enables or disables the function to ping the virtual IP address of the 
virtual router. The standard protocol of VRRP does not support the ping function, 
then the user cannot judge with ping command whether an IP address is used by 
the virtual router. If the user configure the IP address for the host same as the 
virtual IP address of the virtual router, then all messages in this segment will be 
forwarded to the host.
So 3Com Switch 8800 Family Series Routing Switches (hereinafter referred to as 
Switch 8800 Family series) provide the ping function to ping the virtual IP address 
of the virtual router.
Perform the following configuration in system view.
By default, the function to ping the virtual IP address is enabled.
You should set the ping function before configuring the virtual router. If a virtual 
router is already established on the switch, it is not allowed to use the vrrp 
ping-enable
 command and the undo vrrp ping-enable command to modify the 
configuration any more.
Enabling/Disabling the 
Check of TTL Value of 
VRRP Packet
This operation configures whether to check TTL value of VRRP packet on the 
Backup switch. The TTL value must be 225. If the Backup switch find TTL is not 
225 when receiving VRRP packet, the packet will be discarded.
Perform the following configuration in VLAN interface view.
By default, the switch checks TTL value of VRRP packets.
Setting Correspondence 
between Virtual IP 
Address and MAC 
Address
This operation sets correspondence between the virtual lP address and the MAC 
address. In the standard protocol of VRRP, the virtual IP address of the virtual 
router corresponds to the virtual MAC address, to ensure correct data forwarding 
in the sub-net.
Due to the chips installed, some switches support matching one IP address to 
multiple MAC addresses.
Switch 8800 Family series not only guarantee correct data forwarding in the 
sub-net, but also support such function: the user can choose to match the virtual 
IP address with the real MAC address or virtual MAC address of the routing 
interface.
Table 592   Enable/disable the ping function
Operation 
Command 
Enable to ping the virtual IP address 
vrrp ping-enable 
Disable to ping the virtual IP address 
undo vrrp ping-enable
Table 593   Enable/disable the check of TTL value of VRRP packet
Operation 
Command 
Disable the check of TTL value of VRRP packet  vrrp un-check ttl 
Enable the check of TTL value of VRRP packet  undo vrrp un-check ttl