IP address classes vs CIDR (was Re: Reviving ARPAnet)

Grant Taylor cctalk at gtaylor.tnetconsulting.net
Thu Jan 18 13:37:28 CST 2018

On 01/18/2018 12:23 PM, Dennis Boone via cctalk wrote:
> You all talk about Proxy ARP in the past tense for some reason. :)

Please don't interpret the fact that I am inadvertently talking about 
Proxy ARP in the past tense to mean anything.

I personally started solving the problem that Proxy ARP is meant to 
solve with a different solution.

I fell in love with Linux bridges (brctl, etc) for things like this (I'm 
guessing) 15+ years ago.  I can create a Bridging Router (a.k.a. 
BROUTER) that combines layer 2 and layer 3 functionality.  This allowed 
me to bridge non-IP protocols, like NetBIOS / IPX, while routing IP.

I could further extend things to include selectively bridging IP via 
adding EBTables to the mix.

I did a LOT of crazy things with Linux bridges.  }:-)

In hind sight, Proxy ARP might have been the simpler solution.  Though I 
think Proxy ARP would have required that I configure IPs to be Proxy 
ARPed on all intermediate hosts.  Where as bridging has it's own 
inherent L2 learning.  (At least when I was working with non-IP protocols.)

I don't know how well Proxy ARP plays with things like OpenVPN or 
OpenSSH layer 2 tunnels.  -  I know that I can easily extend layer 2 
across a LARGE majority of networks using Linux bridges.  -  I think 
that I can even bridge any type of network that uses 802.2 Link Level 
Control headers.  I.e. Token Ring (802.5) and Ethernet (802.3) and 
Wireless (802.11) and various tunnels.

Grant. . . .
unix || die

More information about the cctalk mailing list