upstream interfaces in dhcrelay
jbradsha at enterasys.com
Mon Apr 20 19:55:30 UTC 2009
According to the man page for dhcrelay (version 4.1.0)
Specifies the ''upper'' network interface for DHCPv6 relay mode:
the interface to which queries from clients and other relay
agents should be forwarded. At least one -u option must be
included in the command line when running in DHCPv6 mode. The
interface name ifname is a mandatory parameter. The destination
unicast or multicast address can be specified by address%; if
not specified, the relay agent will forward to the DHCPv6
All_DHCP_Relay_Agents_and_Servers multicast address.
If appears that relayed packets are routed normally by the ip stack (i.e. the egress interface is determined solely by the destination address) and do not necessarily egress through the specified interface. I am using linux 18.104.22.168. Can someone please answer either or both of the following questions:
1) Why should a user have to specify the egress interface (obviously the server address is required) for relayed messages-shouldn't such messages just be routed normally?
2) Is the linux behavior correct given that the egress interface is specified (as it is in send_packet6)? Shouldn't the sendmsg() return with an EUNREACH error rather than ignore the control message and use the routing tables?
Thanks very much.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the dhcp-workers