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To view if Proxy ARP is enabled on the interface, use the
show config
command in INTERFACE mode. If it is not listed in the
show config
command output, it is enabled. Only non-default information is displayed in the
show config
command output.
Clearing ARP Cache
To clear the ARP cache of dynamically learnt ARP information, use the following command.
•
Clear the ARP caches for all interfaces or for a specific interface by entering the following information.
EXEC privilege
clear arp-cache [
interface
|
ip ip-address
] [no-refresh]
–
ip
ip-address
(OPTIONAL): enter the keyword
ip
then the IP address of the ARP entry you wish to clear.
–
no-refresh
(OPTIONAL): enter the keywords
no-refresh
to delete the ARP entry from CAM. Or to specify which
dynamic ARP entries you want to delete, use this option with
interface
or
ip ip-address
.
– For a 10-Gigabit Ethernet interface, enter the keyword
TenGigabitEthernet
then the slot/port[/subport] information.
– For a 40-Gigabit Ethernet interface, enter the keyword
fortyGigE
then the slot/port information.
– For a port channel interface, enter the keywords
port-channel
then a number.
– For a VLAN interface, enter the keyword
vlan
then a number from 1 to 4094.
NOTE: Transit traffic may not be forwarded during the period when deleted ARP entries are resolved again and re-
installed in CAM. Use this option with extreme caution.
ARP Learning via Gratuitous ARP
Gratuitous ARP can mean an ARP request or reply.
In the context of ARP learning via gratuitous ARP on Dell Networking OS, the gratuitous ARP is a request. A gratuitous ARP request
is an ARP request that is not needed according to the ARP specification, but one that hosts may send to:
•
detect IP address conflicts
•
inform switches of their presence on a port so that packets can be forwarded
•
update the ARP table of other nodes on the network in case of an address change
In the request, the host uses its own IP address in the Sender Protocol Address and Target Protocol Address fields.
Enabling ARP Learning via Gratuitous ARP
To enable ARP learning via gratuitous ARP, use the following command.
•
Enable ARP learning via gratuitous ARP.
CONFIGURATION mode
arp learn-enable
ARP Learning via ARP Request
In Dell Networking OS versions prior to 8.3.1.0, Dell Networking OS learns via ARP requests only if the target IP specified in the
packet matches the IP address of the receiving router interface. This is the case when a host is attempting to resolve the gateway
address.
If the target IP does not match the incoming interface, the packet is dropped. If there is an existing entry for the requesting host, it is
updated.
IPv4 Routing
411
Summary of Contents for S4048-ON
Page 1: ...Dell Configuration Guide for the S4048 ON System 9 9 0 0 ...
Page 146: ...Figure 14 BFD Three Way Handshake State Changes 146 Bidirectional Forwarding Detection BFD ...
Page 522: ...Figure 87 Configuring Interfaces for MSDP 522 Multicast Source Discovery Protocol MSDP ...
Page 523: ...Figure 88 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 523 ...
Page 528: ...Figure 91 MSDP Default Peer Scenario 1 528 Multicast Source Discovery Protocol MSDP ...
Page 529: ...Figure 92 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 529 ...
Page 530: ...Figure 93 MSDP Default Peer Scenario 3 530 Multicast Source Discovery Protocol MSDP ...
Page 633: ...Policy based Routing PBR 633 ...
Page 777: ...Figure 119 Single and Double Tag TPID Match Service Provider Bridging 777 ...
Page 778: ...Figure 120 Single and Double Tag First byte TPID Match 778 Service Provider Bridging ...