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<p class=MsoNormal>Hello,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>According to the man page for dhcrelay (version 4.1.0)<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>-u [address%]ifname<o:p></o:p></p>
<p class=MsoNormal>
Specifies the ''upper'' network interface for DHCPv6 relay mode:<o:p></o:p></p>
<p class=MsoNormal>
the interface to which queries from clients and
other relay<o:p></o:p></p>
<p class=MsoNormal>
agents should be forwarded. At least one -u
option must be<o:p></o:p></p>
<p class=MsoNormal>
included in the command line when running in DHCPv6 mode. The<o:p></o:p></p>
<p class=MsoNormal>
interface name ifname is a mandatory parameter. The destination<o:p></o:p></p>
<p class=MsoNormal>
unicast or multicast address can be specified by address%; if<o:p></o:p></p>
<p class=MsoNormal>
not specified, the relay agent will
forward to the DHCPv6<o:p></o:p></p>
<p class=MsoNormal>
All_DHCP_Relay_Agents_and_Servers multicast address.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>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 2.6.21.7. Can someone please answer either or both of the following
questions:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='mso-list:Ignore'>1)<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>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?<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='mso-list:Ignore'>2)<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>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?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks very much.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Ted Bradshaw<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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