HP 6125XLG R2306-HP 6125XLG Blade Switch High Availability Command Reference - Page 76

vrrp check-ttl enable

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Predefined user roles network-admin Parameters interface interface-type interface-number: Specifies an interface by its type and number. vrid virtual-router-id: Specifies an IPv4 VRRP group by its virtual router ID in the range of 1 to 255. Usage guidelines If no interface or VRRP group is specified, this command clears statistics for all IPv4 VRRP groups. If only an interface is specified, this command clears statistics for all IPv4 VRRP groups on the specified interface. If both an interface and an IPv4 VRRP group are specified, this command clears statistics for the specified IPv4 VRRP group on the specified interface. Examples # Clear statistics for all IPv4 VRRP groups on all interfaces. reset vrrp statistics Related commands display vrrp statistics vrrp check-ttl enable Use vrrp check-ttl enable to enable TTL check for IPv4 VRRP packets. Use undo vrrp check-ttl enable to disable TTL check for IPv4 VRRP packets. Syntax vrrp check-ttl enable undo vrrp check-ttl enable Default TTL check for IPv4 VRRP packets is enabled. Views Interface view Predefined user roles network-admin Usage guidelines The master in an IPv4 VRRP group periodically sends VRRP advertisements to declare its presence. The VRRP advertisements are multicast in the local subnet and cannot be forwarded by routers, so the TTL value is not changed. When the master sends VRRP advertisements, it sets the TTL value to 255. If you enable TTL check, the backups drop the VRRP advertisements with TTL other than 255, preventing attacks from other subnets. Devices from different vendors might implement VRRP differently. When the device is interoperating with devices of other vendors, TTL check on VRRP packets might result in unexpected dropping of packets. In this scenario, use the undo vrrp check-ttl enable command to disable TTL check on VRRP packets. 71

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71
Predefined user roles
network-admin
Parameters
interface
interface-type interface-number
: Specifies an interface by its type and number.
vrid
virtual-router-id
: Specifies an IPv4 VRRP group by its virtual router ID in the range of 1 to 255.
Usage guidelines
If no interface or VRRP group is specified, this command clears statistics for all IPv4 VRRP groups. If only
an interface is specified, this command clears statistics for all IPv4 VRRP groups on the specified interface.
If both an interface and an IPv4 VRRP group are specified, this command clears statistics for the specified
IPv4 VRRP group on the specified interface.
Examples
# Clear statistics for all IPv4 VRRP groups on all interfaces.
<Sysname> reset vrrp statistics
Related commands
display vrrp
statistics
vrrp check-ttl enable
Use
vrrp check-ttl enable
to enable TTL check for IPv4 VRRP packets.
Use
undo vrrp check-ttl enable
to disable TTL check for IPv4 VRRP packets.
Syntax
vrrp check-ttl enable
undo vrrp check-ttl enable
Default
TTL check for IPv4 VRRP packets is enabled.
Views
Interface view
Predefined user roles
network-admin
Usage guidelines
The master in an IPv4 VRRP group periodically sends VRRP advertisements to declare its presence. The
VRRP advertisements are multicast in the local subnet and cannot be forwarded by routers, so the TTL
value is not changed. When the master sends VRRP advertisements, it sets the TTL value to 255. If you
enable TTL check, the backups drop the VRRP advertisements with TTL other than 255, preventing attacks
from other subnets.
Devices from different vendors might implement VRRP differently. When the device is interoperating with
devices of other vendors, TTL check on VRRP packets might result in unexpected dropping of packets. In
this scenario, use the
undo
vrrp
check-ttl
enable
command to disable TTL check on VRRP packets.