01-27-2016 02:30 PM - edited 03-05-2019 03:13 AM
Is there a command or feature that can simulate the static arp command but with an entire netmask ? I have been digging with no luck.
Basically.
arp vrf A 10.10.10.0. 255.255.255.0 MAC-address arpa?
01-27-2016 03:05 PM
You want to return a single MAC address for every IP in the subnet?
01-27-2016 05:43 PM
Yes
01-28-2016 02:25 AM
Hello Astoffel1,
you should look at Proxy ARP instead, but I don't know if Cisco routers support it for hosts within the same subnet. But this would be the mechanism to use, otherwise you need many arp statements to emulate all the hosts in a subnet.
An ARP entry is intended for a single host so it cannot have a netmask.
Hope to help
Giuseppe
01-28-2016 02:30 AM
Basically the statically defined MAC addresses will prevent the router from sending an ARP request, and look it up locally.
This sounds like something you could do with a simple route or route-map.
Where is 10.10.10.0/24 relative to the router? Is is a directly connected interface? Are you wanting to send all the traffic to a single host?
01-28-2016 08:48 AM
They're directly connect logically, right now what happens is that the Routers are running OSPF and receive the multicast hell, but get stuck in INT because they can not send the unicast response because in the ARP table it doesn't have an entry for that address.
The solution I have know is a TCL script that adds a static arp per OSPF neighbor, but I would like not to depend on a script for Routing. And not there is multiple Routers connected to this interface.
01-28-2016 10:20 AM
If they are stuck in INIT it is because they have not seen each other's router IDs in the hello packets.
Not sure where unicast comes into it because the hellos are multicast.
From each router what do you get if you ping 224.0.0.5 ?
Jon
01-28-2016 12:02 PM
*** Double oops my mistake ***
01-28-2016 12:04 PM
So the router sends an ARP request for the remote OSPF neighbours address. What is preventing the remote device from responding?
Could you post the OSPF config of two of the affected routers?
01-28-2016 02:32 PM
There is a device that cannot proxy arp in between each router. I am running Point to multipoint OSPF.
Basically the config is
R1 -Device 1 ----"Cloud"---Device 2 -R2.
Manually adding the ARP will bring up OSPF neighbors, so now I have a TCL that will create the Static ARP dynamically. I was wondering if there might be a cisco configuration instead.
01-28-2016 02:36 PM
What kind of circuit or WAN connection is this that causes the remote end not to respond to ARP?
01-28-2016 02:52 PM
Hello,
edited.
It happens when you start OSPF process or after some while? Are you using secondary IP address in those interfaces? How routers are connected to each others?
Masoud
01-28-2016 03:05 PM
Start the OSPF process and no I am not using a secondary IP, it will be connected to about 20
01-28-2016 02:34 PM
I will give this a try it looks promising at a glance.
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