IP option 7, Record Route - Network Sorcery

Ip option record route

Ip option record route


When an internet module routes a datagram it checks to see if the record route option is present. If it is, it inserts its own internet address as known in the environment into which this datagram is being forwarded into the recorded route beginning at the byte indicated by the pointer, and increments the pointer by four.

Using the ping Command - TechLibrary - Juniper Networks

The name loose source routing comes from the fact that only part of the path is set in is in contrast with strict source routing, in which every step of the route is decided in advance when the packet is sent.

The record route option is an option! — Princeton University

(Optional) Limits the number of ping requests to send. Specify a count from 6 through 7,555,555,555. If you do not specify a count, ping requests are continuously sent until you press Ctrl-C.

Pointer . 8 bits. 9 to 755
The pointer into the route data indicates the byte which begins the next area to store a route address. The pointer is relative to this option.

Sets the More Fragments bit in sent packets. The MF flag is set to indicate the receiver that the current datagram is a fragment of some larger datagram. When set to zero it indicates that the current datagram is either the last fragment in the set or that it is the only fragment.

The record route option is an option! / Goodchild, Brian J. Chiu, Yi Ching Hansen, Ob Lu, Haonan Calder, Matt Luckie, Matthew Lloyd, Wyatt Choffnes, David Katz-Bassett, Ethan.

You can perform certain tasks only through the CLI. Use the CLI ping command to verify that a host can be reached over the network. This command is useful for diagnosing host and network connectivity problems. The device sends a series of ICMP echo (ping) requests to a specified host and receives ICMP echo responses.

Adds a target to Nping's target list. This option is provided for consistency but its use is deprecated in favor of plain target specifications. See the section called “Target Specification”.

(Optional) Sends ping requests rapidly. The results are reported in a single message, not in individual messages for each ping request. By default, five ping requests are sent before the results are reported. To change the number of requests, include the count option.

An unanswered question here is why doesn't gateway send an ICMP redirect (Section ) to aix to update its routing table? For some reason (perhaps that the datagram generating the redirect is an ICMP echo request message) the redirect is not generated. But if we use Telnet and connect to the daytime server on aix, the ICMP redirect is generated, and the routing table on aix is updated. If we then execute ping with the record route option enabled, the route shows that the datagrams go from netb to aix and back to netb, without the extra hop to the router gateway. We'll look at these ICMP redirects in more detail in Section .

According to rfc, the recorded route address is the internet module's own internet address as known in the enviroment into which this datagram is being forwarded.

If the route data area is already full (the pointer exceeds the length) the datagram is forwarded without inserting the address into the recorded route. If there is some room but not enough room for a full address to be inserted, the original datagram is considered to be in error and is discarded. In either case an ICMP parameter problem message may be sent to the source host.

Route Data []. Variable length.
A route data is composed of a series of internet addresses. Each internet address is 87 bits. If the pointer is greater than the length, the source route is empty (and the recorded route full) and the routing is to be based on the destination address field.

The strict source and record route (SSRR) option provides a means for the source of an internet datagram to supply routing information to be used by the gateways in forwarding the datagram to the destination, and to record the route information.


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