ARPResponder Element Documentation

ARPResponder -- Click element; generates responses to ARP queries

ARPResponder(IP/MASK1 [IP/MASK...] ETH1, IP/MASK2 ETH2, ...)

Ports: 1 input, 1 output
Processing: agnostic
Package: ethernet (core)

Input should be ARP request packets, including the Ethernet header. Forwards an ARP reply if we know the answer -- that is, if one of the IPPREFIX arguments matches the requested IP address, then it outputs an ARP reply giving the corresponding ETH address. Could be used for proxy ARP as well as producing replies for a host's own address. The IP/MASK arguments are IP network addresses (IP address/netmask pairs). The netmask can be specified in CIDR form (`18.26.7.0/24') or dotted decimal form (`18.26.7.0/255.255.255.0'). ARPResponder sets the device annotations on generated ARP responses to the device annotations from the corresponding queries.

AddressInfo elements can simplify the arguments to ARPResponder. In particular, if NAME is shorthand for both an IP network address (or IP address) IP and an Ethernet address ETH, then ARPResponder(NAME) is equivalent to ARPResponder(IP ETH). If NAME is short for both an IP address and an IP network address, then ARPResponder will prefer the IP address. (You can say NAME:ipnet to use the IP network address.)

Produce ARP replies for the local machine (18.26.4.24) as well as proxy ARP for all machines on net 18.26.7 directing their packets to the local machine:

  c :: Classifier(12/0806 20/0001, ...);
  ar :: ARPResponder(18.26.4.24 18.26.7.0/24 00:00:C0:AE:67:EF);
  c[0] -> ar;
  ar -> ToDevice(eth0);

ARPQuerier, ARPFaker, AddressInfo

Generated by 'click-elem2man' from '../elements/ethernet/arpresponder.hh' on 20/Feb/2006.