blank.gif (43 bytes)

Church Of The
Swimming Elephant

Search:
APPENDIX A. REQUIREMENTS FOR SOURCE-ROUTING HOSTS Connected: An Internet Encyclopedia
APPENDIX A. REQUIREMENTS FOR SOURCE-ROUTING HOSTS

Up: Connected: An Internet Encyclopedia
Up: Requests For Comments
Up: RFC 1812
Prev: 11. REFERENCES
Next: APPENDIX B. GLOSSARY

APPENDIX A. REQUIREMENTS FOR SOURCE-ROUTING HOSTS

APPENDIX A. REQUIREMENTS FOR SOURCE-ROUTING HOSTS

Subject to restrictions given below, a host MAY be able to act as an intermediate hop in a source route, forwarding a source-routed datagram to the next specified hop.

However, in performing this router-like function, the host MUST obey all the relevant rules for a router forwarding source-routed datagrams [INTRO:2]. This includes the following specific provisions:

  1. TTL
    The TTL field MUST be decremented and the datagram perhaps discarded as specified for a router in [INTRO:2].

  2. ICMP Destination Unreachable
    A host MUST be able to generate Destination Unreachable messages with the following codes:
    4 (Fragmentation Required but DF Set) when a source-routed datagram cannot be fragmented to fit into the target network;
    5 (Source Route Failed) when a source-routed datagram cannot be forwarded, e.g., because of a routing problem or because the next hop of a strict source route is not on a connected network.

  3. IP Source Address
    A source-routed datagram being forwarded MAY (and normally will) have a source address that is not one of the IP addresses of the forwarding host.

  4. Record Route Option
    A host that is forwarding a source-routed datagram containing a Record Route option MUST update that option, if it has room.

  5. Timestamp Option
    A host that is forwarding a source-routed datagram containing a Timestamp Option MUST add the current timestamp to that option, according to the rules for this option.

To define the rules restricting host forwarding of source-routed datagrams, we use the term local source-routing if the next hop will be through the same physical interface through which the datagram arrived; otherwise, it is non-local source-routing.

A host is permitted to perform local source-routing without restriction.

A host that supports non-local source-routing MUST have a configurable switch to disable forwarding, and this switch MUST default to disabled.

The host MUST satisfy all router requirements for configurable policy filters [INTRO:2] restricting non-local forwarding.

If a host receives a datagram with an incomplete source route but does not forward it for some reason, the host SHOULD return an ICMP Destination Unreachable (code 5, Source Route Failed) message, unless the datagram was itself an ICMP error message.


Next: APPENDIX B. GLOSSARY

Connected: An Internet Encyclopedia
APPENDIX A. REQUIREMENTS FOR SOURCE-ROUTING HOSTS

Cotse.Net

Protect yourself from cyberstalkers, identity thieves, and those who would snoop on you.
Stop spam from invading your inbox without losing the mail you want. We give you more control over your e-mail than any other service.
Block popups, ads, and malicious scripts while you surf the net through our anonymous proxies.
Participate in Usenet, host your web files, easily send anonymous messages, and more, much more.
All private, all encrypted, all secure, all in an easy to use service, and all for only $5.95 a month!

Service Details

 
.
www.cotse.com
Have you gone to church today?
.
All pages ©1999, 2000, 2001, 2002, 2003 Church of the Swimming Elephant unless otherwise stated
Church of the Swimming Elephant©1999, 2000, 2001, 2002, 2003 Cotse.com.
Cotse.com is a wholly owned subsidiary of Packetderm, LLC.

Packetderm, LLC
210 Park Ave #308
Worcester, MA 01609