Greetings. I have a particular use case and am considering using RouterBOARDs. Here is my question:

Where can I find information on the ARP limit of RouterBOARD hardware? In particular, I am looking for a RouterBOARD model that will support 4k ARPs (3750 is my total number of IP addresses).

The use case is this: in a data center I have management switches that connect to server mgmt and IPMI connections. These switches are aggregated and must come back to a router. I would like to IP terminate two VLANs as IP interfaces on a RouterBOARD.

Thank you.

Maximal number of ARP entries is 8192.

source: http://wiki.mikrotik.com/wiki/Manual:IP/ARP#Properties

according to this, every board can deal with it. OTOH, putting such amount of servers into a single broadcast domain
(even if it is just for their iLO/IPMI traffic) may not be the best idea.

CCR's except 1009 had separated PHY's on each port and thus not restrained to multi-port switch chips limiations. rest are - within ~2k.
(http://wiki.mikrotik.com/wiki/Manual:Sw ... p_Features)
and yep, generally its not sane idea to build "too flat" network with HUGE segments, not only from security but from basic functions of it.

Maximal number of ARP entries is 8192.

source: http://wiki.mikrotik.com/wiki/Manual:IP/ARP#Properties

according to this, every board can deal with it. OTOH, putting such amount of servers into a single broadcast domain
(even if it is just for their iLO/IPMI traffic) may not be the best idea.

I think this is an old Wiki entry. We have changed the max ARP entries to beyond 8192 on multiple CCRs for large Data Center networks and it works.

multi-port switch chips limiations. rest are - within ~2k.
(http://wiki.mikrotik.com/wiki/Manual:Sw ... p_Features)

that resource is the "MAC" table, where the MAC entries learnt by the switch reside. if you have more entries
in the switch, traffic is still passed, albeit via unknown unicast and broadcasted to all ports in the VLAN. [which is essentially bad but works]
whereas without ARP entries no IP communication over ethernet can be made.

I think this is an old Wiki entry. We have changed the max ARP entries to beyond 8192 on multiple CCRs for large Data Center networks and it works.

true dat. this page needs updates.

on most new non-ccr devices numbers bit bigger, but still insane on newer devices
64k ? no problem 128k ? whatever :=)