R2511-HP MSR Router Series Layer 3 - IP Services Configuration Guide(V5)

5
Step Command Remarks
2. Set the aging timer for
dynamic ARP entries.
arp timer aging aging-time
Optional.
20 minutes by default.
Enabling dynamic ARP entry check
The dynamic ARP entry check function controls whether the device supports dynamic ARP entries with
multicast MAC addresses.
When dynamic ARP entry check is enabled, the device cannot learn dynamic ARP entries containing
multicast MAC addresses.
When dynamic ARP entry check is disabled, the device can learn dynamic ARP entries containing
multicast MAC addresses.
To enable dynamic ARP entry check:
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enable dynamic ARP entry
check.
arp check enable
Optional.
Enabled by default.
Enabling natural mask support for ARP requests
This feature enables the device to learn the sender IP and MAC addresses in a received ARP request
whose sender IP address is on the same classful network as but a different subnet from the IP address of
the receiving interface. A classful network refers to a class A, B, or C network.
For example, VLAN-interface 10 with IP address 10.10.10.5/24 receives an ARP request from
10.11.11.1/8. Because the subnet address calculated by the AND operation of 10.11.11.1 a n d t h e 24 - b i t
subnet mask of the receiving interface is not in the subnet 10.10.10.5/24, VLAN-interface 10 cannot
process the ARP packet.
With this feature enabled, the device calculates the subnet address by using the default mask of the class
A network where 10.10.10.5/24 resides. Because 10.10.10.5/24 is on the same class A network as
10.11.11.1/8, VLAN-interface 10 can learn the sender IP and MAC addresses in the request.
To enable natural mask support for ARP requests:
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enable natural mask support for
ARP requests.
naturemask-arp enable Disabled by default.