% % $XORP: xorp/docs/user_manual/ospf.tex,v 1.11 2006/08/02 05:31:48 pavlin Exp $ % \chapter{OSPFv2 and OSPFv3} \label{ospf} \section{OSPF Terminology and Concepts} OSPF is the Open Shortest Path First protocol, it is one of two principle Interior Gateway Protocols (IGP) the other being IS-IS. RIP is also an IGP however OSPF and IS-IS have better scaling properties. The initial OSPF specification is RFC 2328 OSPF Version 2 or OSPFv2. This specification is specific to IPv4. There is a later specification RFC 2740 OSPF for IPv6, which happens to be Version 3 or OSPFv3. The specifications for OSPFv2 and OSPFv3 are fairly similar the obvious difference is the handing of IPv4 and IPv6 addresses. The XORP implementation of OSPF supports both OSPFv2 and OSPFv3 however only OSPFv2 is currently available in Release-1.2. For consistency with our other protocols OSPFv2 is {\tt ospf4} in the configuration files, the {\tt 4} in {\tt ospf4} refers to the IPv4 address family. \subsection{Key OSPF Concepts} As an Interior Gateway Protocol OSPF runs within a single Autonomous System. One way that OSPF achieves good scaling properties is to allow an AS to be split into distinct regions that OSPF calls areas. The areas are structured in a two level hierarchy, area {\tt 0.0.0.0} is special and is called the {\tt BACKBONE} area. All other areas must be connected to that {\tt BACKBONE} either directly or through virtual links. A fundamental quantity in OSPF that describes topology and routing information is the Link State Advertisement (LSA). Every OSPF router within an area should have exactly the same LSAs in its database. There are different type of LSAs the base specification describes Router-LSAs, Network-LSAs, Summary-LSAs and AS-external-LSAs. The OSPF protocol has explicit support for introducing routes from other protocols, these routes are introduced via AS-external-LSAs. For example, routes from a RIP cloud can be introduced into OSPF and will appear as AS-external-LSAs. Areas in OSPF can be one of three different types {\tt normal}, {\tt stub} and {\tt Not-So-Stubby}. The {\tt BACKBONE} is always {\tt normal}. All LSAs in OSPF are flooded only within an area, the exception is the AS-external-LSA that can be flooded between all {\tt normal} areas. OSPF routers are categorised into four overlapping categories, an internal router whose interfaces are all in one area, an area border router ({\tt ABR}) that has interfaces in more than one area, a backbone router that has an interface to the {\tt BACKBONE} and an AS boundary router that introduces routes from other protocols. An AS boundary router can be configured in {\tt normal} and {\tt Not-So-Stubby} areas. In a {\tt normal} area the AS boundary router generates an AS-external-LSA that is flooded to all other {\tt normal} areas. In a {\tt Not-So-Stubby} an AS boundary router generates a Type-7 LSA that {\bf may} be translated at a area border router to an AS-external-LSA, which will be flooded to all {\tt normal} areas. An AS-external-LSA is never flooded into a {\tt stub} or {\tt Not-So-Stubby} area. The different types of areas exist to limit the number of LSAs in a particular area, for example a {\tt stub} area may have a small number of internal routes and default routes to the {\tt ABR}s. \section{Standards} XORP OSPF complies with the following standards: \begin{description} \item{\bf RFC 2328}: OSPF Version 2 \item{\bf RFC 3101}: The OSPF Not-So-Stubby Area (NSSA) Option \end{description} \newpage \section{Configuring OSPF} \subsection{Configuration Syntax} The configuration syntax for XORP OSPFv2 is given below. \vspace{0.1in} \noindent\framebox[\textwidth][l]{\scriptsize \begin{minipage}{6in} \begin{alltt} \begin{tabbing} xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=\kill protocols \{\\ \>ospf4 \{\\ \>\>targetname: {\it text}\\ \>\>router-id: {\it IPv4}\\ \>\>ip-router-alert: {\it bool}\\ \\ \>\>traceoptions \{\\ \>\>\>flag \{\\ \>\>\>\>all \{\\ \>\>\>\>\>disable: {\it bool}\\ \>\>\>\>\}\\ \>\>\>\}\\ \>\>\}\\ \\ \>\>area {\it IPv4} \{\\ \>\>\>area-type: {\it text}\\ \\ \>\>\>default-lsa \{\\ \>\>\>\>disable: {\it bool}\\ \>\>\>\>metric: {\it uint(0..0xffffff)}\\ \>\>\>\}\\ \\ \>\>\>summaries \{\\ \>\>\>\>disable: {\it bool}\\ \>\>\>\}\\ \\ \>\>\>area-range {\it IPv4Net} \{\\ \>\>\>\>advertise: {\it bool}\\ \>\>\>\}\\ \\ \>\>\>virtual-link {\it IPv4} \{\\ \>\>\>\>transit-area: {\it ipv4}\\ \>\>\>\>hello-interval: {\it uint(1..65535)}\\ \>\>\>\>router-dead-interval: {\it uint(1..65535)}\\ \>\>\>\>retransmit-interval: {\it uint(1..65535)}\\ \>\>\>\>transit-delay: {\it uint(0..3600)}\\ \>\>\>\>authentication \{\\ \>\>\>\>\>simple-password: {\it text}\\ \\ \>\>\>\>\>md5 {\it uint(0..255)} \{\\ \>\>\>\>\>\>password: {\it text}\\ \>\>\>\>\>\>start-time: {\it text(``YYYY-MM-DD.HH:MM'')}\\ \>\>\>\>\>\>end-time: {\it text(``YYYY-MM-DD.HH:MM'')}\\ \>\>\>\>\>\>max-time-drift: {\it uint(0..65535)}\\ \>\>\>\>\>\}\\ \>\>\>\>\}\\ \>\>\>\}\\ \\ {\rm continued overleaf....} \end{tabbing} \end{alltt} \end{minipage} } \vspace{0.1in} \newpage \vspace{0.1in} \noindent\framebox[\textwidth][l]{\scriptsize \begin{minipage}{6in} \begin{alltt} \begin{tabbing} xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=xx\=\kill \>\>\>interface {\it text} \{\\ \>\>\>\>link-type: {\it text}\\ \\ \>\>\>\>vif {\it text} \{\\ \\ \>\>\>\>\>address {\it IPv4} \{\\ \>\>\>\>\>\>priority: {\it uint(0..255)}\\ \>\>\>\>\>\>hello-interval: {\it uint(1..65535)}\\ \>\>\>\>\>\>router-dead-interval: {\it uint(1..4294967295)}\\ \>\>\>\>\>\>interface-cost: {\it uint(1..65535)}\\ \>\>\>\>\>\>retransmit-interval: {\it uint(1..65535)}\\ \>\>\>\>\>\>transit-delay: {\it uint(0..3600)}\\ \>\>\>\>\>\>authentication \{\\ \>\>\>\>\>\>\>simple-password: {\it text}\\ \\ \>\>\>\>\>\>\>md5 {\it uint(0..255)} \{\\ \>\>\>\>\>\>\>\>password: {\it text}\\ \>\>\>\>\>\>\>\>start-time: {\it text(``YYYY-MM-DD.HH:MM'')}\\ \>\>\>\>\>\>\>\>end-time: {\it text(``YYYY-MM-DD.HH:MM'')}\\ \>\>\>\>\>\>\>\>max-time-drift: {\it uint(0..65535)}\\ \>\>\>\>\>\>\>\}\\ \>\>\>\>\>\>\}\\ \>\>\>\>\>\>passive: {\it text}\\ \\ \>\>\>\>\>\>neighbor {\it IPv4}\{\\ \>\>\>\>\>\>\>router-id: {\it IPv4}\\ \>\>\>\>\>\>\}\\ \\ \>\>\>\>\>\>disable: {\it bool}\\ \>\>\>\>\>\}\\ \>\>\>\>\}\\ \>\>\>\}\\ \>\>\}\\ \\ \>\>import: {\it text} \\ \>\>export: {\it text}\\ \>\}\\ \} \end{tabbing} \end{alltt} \end{minipage} } \vspace{0.1in} \noindent The configuration parameters are used as follows: \begin{description} \item{\tt protocols}: This delimits the configuration for all routing protocols in the XORP router configuration. It is mandatory that OSPF configuration is under the {\stt protocols} node in the configuration. \item{\tt ospf4}: This delimits the OSPF configuration part of the XORP router configuration. \item{\tt targetname}: This is the name for this instance of OSPF. It defaults to ``{\stt ospfv2}'', and it is not recommended that this default is overridden under normal usage scenarios. \item{\tt router-id}: This is a unique IPv4 address within the Autonomous System. The smallest IP address of an interface belonging to the router is a good choice. The required format of the {\stt router-id} is a dotted-decimal IPv4 address. \item{\tt ip-router-alert}: This takes the value {\stt true} or {\stt false}. The default state is {\stt false}, if set to {\stt true} the IP router alert option will be placed in all transmitted packets. \item{\tt traceoptions}: This directive if present will enable all tracing. \item{\tt area}: This delimits an area in which multiple virtual links and interfaces can be configured. The {\stt area} directive take an area identifier parameter, which by convention is specified as a dotted-decimal IPv4 address. \begin{description} \item{\tt area-type}: This is the type of the area, {\stt normal}, {\stt stub} or {\stt nssa}. \item{\tt default-lsa}: This directive if present is affective for {\stt stub} or {\stt nssa} areas only. If the router is an Area Border Router, then a default-lsa will be introduced into this area. \begin{description} \item{\tt metric}: This is the metric in the default-lsa. \item{\tt disable}: This takes the value {\stt true} or {\stt false}. The default setting is {\stt false} it can be set to {\stt true} to disable the sending of the default-lsa. \end{description} \end{description} \begin{description} \item{\tt summaries}: This directive if present is affective for {\stt stub} or {\stt nssa} areas only. If the router is an Area Border Router, then this option controls the introduction of Summary-LSAs into the area. \begin{description} \item{\tt disable}: This takes the value {\stt true} or {\stt false}. The default setting is {\stt false} it can be set to {\stt true} to disable the sending of Summary-LSAs. \end{description} \end{description} \begin{description} \item{\tt area-range}: If the router is an Area Border Router the IPv4 network defines how to summarize this area into other areas. \begin{description} \item{\tt advertise}: This takes the value {\stt true} or {\stt false}. The default setting is {\stt true} it can be set to {\stt false} to disable the sending of Summary-LSAs. \end{description} \end{description} \begin{description} \item{\tt virtual-link}: This is the {\stt router-id} of the router with which a virtual link should be formed. Virtual links can only be configured in the {\stt BACKBONE} area. The format of the parameter is a dotted-decimal IPv4 address. \begin{description} \item{\tt transit-area}: This is the transit area through which the virtual link is formed. \item{\tt hello-interval}: This is the time in seconds between sending hello packets. \item{\tt router-dead-interval}: This is the time in seconds to wait before considering a neighbor dead. If no hello packets are seen from the neighbor in this time then it is considered dead. \item{\tt retransmit-interval}: This is the time in seconds between retransmitting various packets, such as link state update packets or link state request packets. \item{\tt authentication}: This directive specifies the authentication mechanism used to authorise OSPF updates sent and received via this vif/address. The authentication is configured by using one of the following mutually-exclusive statements: \begin{description} \item{\tt simple-password}: this specifies the password used for plaintext authentication on this vif/address. \item{\tt md5}: this specifies an MD5 authentication key. The parameter is the key ID and must be in the interval [0, 255]. The MD5 authentication is configured by using the following statements: \begin{description} \item{\tt password}: this specifies the MD5 password for the specific key. \item{\tt start-time}: this specifies the start time when the key becomes active. The format is ``YYYY-MM-DD.HH:MM''. If it is empty, then the key should become active immediately. \item{\tt end-time}: this specifies the end time when the key becomes inactive. The format is ``YYYY-MM-DD.HH:MM''. If it is empty, then the key should never expire. \item{\tt max-time-drift}: this specifies the maximum time drift (in seconds) among all OSPF routers. The allowed values are in the interval [0, 65535]. If the value is 65535, the time drift is unlimited. The purpose of this statement is to decide when to start accepting the MD5 keys in case other routers's clocks are not syncronized and have started to generate messages with a particular key: \begin{description} \item KeyStartAccept = KeyStartGenerate - MaxTimeDrift \item KeyStopAccept = KeyStopGenerate + MaxTimeDrift \end{description} \end{description} If there are multiple configured keys, among the keys that are valid for message generation, the one with the most recent {\stt start-time} (and the largest key ID as a tie breaker) would be used to generate the messages. \end{description} \end{description} \item{\tt interface}: This specifies a network interface that should be used by OSPF for routing. See Chapter \ref{interfaces} for details of interfaces. The interface must be configured in the {\stt interfaces} part of the router configuration. \begin{description} \item{\tt link-type}: This specifies the type of the link, {\stt broadcast}, {\stt p2p} (Point-to-Point) or {\stt p2m} (Point-to-Multipoint). \begin{description} \item{\tt vif}: This specifies a vif that should be used by OSPF for routing. See Chapter \ref{interfaces} for details of vifs. \begin{description} \item{\tt address}: This specifies an IPv4 address that should be used by OSPF for routing. OSPF will peer with other routers on this {\stt interface/vif} using this {\stt address}. The address must be a valid configured address for this vif. The parameters that can be specified for each address are: \begin{description} \item{\tt priority}: This is the priority used to select the Designated Router on a {\stt broadcast} or {\stt nbma} {\stt link-type}. The priorities range from 0 to 255. If a value of 0 is choosen this router will not be a candidate to become the Designated Router \item{\tt hello-interval}: This is the time in seconds between sending hello packets. \item{\tt router-dead-interval}: This is the time in seconds to wait before considering a neighbor dead. If no hello packets are seen from the neighbor in this time then it is considered dead. \item{\tt interface-cost}: The cost for this address that is placed in the Router-LSA. \item{\tt retransmit-interval}: This is the time in seconds between retransmitting various packets, such as link state update packets or link state request packets. \item{\tt transit-delay}: The time to transmit an LSA on this address, this value is added to the age field of all LSAs. \item{\tt authentication}: This directive specifies the authentication mechanism used to authorise OSPF updates sent and received via this vif/address. The authentication is configured by using same configuration statements as those in case of virtual links (see the {\tt virtual-link} configuration statement above). %% The authentication is configured by using one of the following %% mutually-exclusive statements: %% \begin{description} %% \item{\tt simple-password}: this specifies the password used for %% plaintext authentication on this vif/address. %% \item{\tt md5}: this specifies an MD5 authentication key. The parameter %% is the key ID and must be in the interval [0, 255]. %% The MD5 authentication is configured by using the following %% statements: %% \begin{description} %% \item{\tt password}: this specifies the MD5 password for the specific %% key. %% \item{\tt start-time}: this specifies the start time when the key %% becomes active. The format is ``YYYY-MM-DD.HH:MM''. If it is empty, %% then the key should become active immediately. %% \item{\tt end-time}: this specifies the end time when the key becomes %% inactive. The format is ``YYYY-MM-DD.HH:MM''. If it is empty, %% then the key should never expire. %% \item{\tt max-time-drift}: this specifies the maximum time drift %% (in seconds) among all OSPF routers. The allowed values are in the %% interval [0, 65535]. If the value is 65535, the time drift is %% unlimited. The purpose of this statement is to decide when to start %% accepting the MD5 keys in case other routers's clocks are not %% syncronized and have started to generate messages with a particular %% key: %% \begin{description} %% \item KeyStartAccept = KeyStartGenerate - MaxTimeDrift %% \item KeyStopAccept = KeyStopGenerate + MaxTimeDrift %% \end{description} %% \end{description} %% \end{description} \item{\tt passive}: This takes the value {\stt true} or {\stt false}. The default setting is {\stt false} it can be set to {\stt true} to set the interface in loopback. The protocol is no longer run on this address and the Router-LSA contains a host route for this address. \item{\tt neighbor}: This allows neighbors to be configured for {\stt link-type}s of {\stt p2p} or {\stt p2m}. The parameter is the IPv4 address of the neighbor. The {\stt router-id} of the neighbor must also be configured. %% \begin{description} %% \item{\tt router-id}: %% \end{description} \item{\tt disable}: This takes the value {\stt true} or {\stt false}. The default setting is {\stt false} it can be set to {\stt true} to disable OSPF on this address without removing all the configuration. \end{description} \end{description} \end{description} \end{description} \end{description} \end{description} \subsection{Example Configurations} \vspace{0.1in} \noindent\framebox[\textwidth][l]{\scriptsize \begin{minipage}{6in} \begin{alltt} \begin{tabbing} xx\=xx\=xx\=xx\=xx\=\kill protocols \{\\ \>ospf4 \{\\ \>\>router-id: 10.10.10.10\\ \\ \>\>area 0.0.0.0 \{\\ \>\>\>interface dc0 \{\\ \>\>\>\>vif dc0 \{\\ \>\>\>\>\>address 10.10.10.10 \{\\ \>\>\>\>\>\}\\ \>\>\>\>\}\\ \>\>\>\}\\ \>\>\}\\ \>\}\\ \}\\ \end{tabbing} \end{alltt} \end{minipage} } This configuration is an example of the minimal possible configuration. OSPF is running in the {\tt BACKBONE} area, on a single interface/vif the {\tt router-id} is set to the interface/vif address. \newpage \section{Monitoring OSPF} On a router running OSPF, the OSPF routing state can be displayed using the {\stt show ospf4} operational-mode command. Information is available about the per area LSA databases and the status of OSPF adjacencies. used. As always, command completion using $<$TAB$>$ or ? will display the available sub-commands and parameters: \vspace{0.1in} \noindent\framebox[\textwidth][l]{\scriptsize \begin{minipage}{6in} \begin{alltt} \begin{tabbing} xx\=xxxxxxxxxxxxxxxxxxxxx\=\kill user@hostname> \textbf{show ospf4 ?}\\ Possible completions:\\ \>database\>Show LSA database\\ \>neighbor\>Show Neighbors\\ \>|\>Pipe through a command\\ \end{tabbing} \end{alltt} \end{minipage} } The {\stt show ospf4 database} command will display information about the LSAs in the database. Many optional parameters are available to narrow the search to specific LSA type or to an area. The optional parameter {\stt detail} will print more information about a LSA. The optional parameter {\stt summary} prints a count of the LSAs. \vspace{0.1in} \noindent\framebox[\textwidth][l]{\scriptsize \begin{minipage}{6in} \begin{alltt} \begin{tabbing} xx\=xxxxxxxxxxxxxxxxxxxxx\=\kill user@hostname> \textbf{show ospf4 database ?}\\ Possible completions:\\ \><[Enter]>\>Execute this command\\ \> area \>Show LSA database\\ \> asbrsummary \>Show Summary-LSA (AS boundary router) database\\ \> brief \>Display brief output (default)\\ \> detail \>Display detailed output\\ \> external \>Show External-LSA database\\ \> netsummary \>Show Summary-LSA (network) database\\ \> network \>Show Network-LSA database\\ \> nssa \>Show NSSA-LSA database\\ \> router \>Show Router-LSA database\\ \> summary \>Display summary output\\ \>|\>Pipe through a command\\ \end{tabbing} \end{alltt} \end{minipage} } \newpage The {\stt show ospf4 database} command with no modifiers will show all LSA types in all areas: \vspace{0.1in} \noindent\framebox[\textwidth][l]{\scriptsize \begin{minipage}{6in} \begin{alltt} \begin{tabbing} %%\=xxxxxxxxx\=xxxxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxxxx\=xxxxxxxx\=xxxxxxxx\=xxxxxxxx\=xxxxxxxx\=xxxxxxxx\=xxxxxxxx\=\kill user@hostname> \textbf{show ospf4 database}\\ OSPF link state database, Area 0.0.0.0\\ \=xxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxx\=xxxxx\=xxxxx\=xxxxxxx\=\kill \>Type\> ID\> Adv Rtr\> Seq\> Age\> Opt\> Cksum\> Len\\ \=xxxxxxxx\=x\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxx\=xxxxx\=xxxxx\=xxxxxxx\=\kill \>Router\>*\> 192.150.187.112\>192.150.187.112\>0x8000018f\>1444\>0x2\> 0x9d24\> 36\\ \>Network\>\> 192.150.187.99\> 192.150.187.99\> 0x80000054\> 167\> 0x22\> 0x7c63\> 40\\ \>SummaryN\>*\>172.16.0.0\> 192.150.187.112\> 0x80000188\> 1453\> 0x2\> 0x9df5\> 28\\ \>SummaryN\>*\>172.16.1.0\> 192.150.187.112\> 0x80000188\> 1453\> 0x2\> 0x92ff\> 28\\ \>SummaryN\>*\>172.16.2.0\> 192.150.187.112\> 0x80000188\> 1453\> 0x2\> 0x870a\> 28\\ \>Router\>\> 192.150.187.99\> 192.150.187.99\> 0x80000e76\> 167\> 0x22\> 0xddf7\> 36\\ \>Router\>\> 192.150.187.5\> 192.150.187.5\> 0x800004a6\> 983\> 0x2\> 0x40a8\> 36\\ \>Router\>\> 192.150.187.108\> 192.150.187.108\> 0x80000301\> 598\> 0x2\> 0xb9a1\> 36\\ \>ASExt-2\>\> 172.16.0.0\> 192.150.187.5\> 0x800003a9\> 990\> 0x2\> 0x77c1\> 36\\ OSPF link state database, Area 0.0.0.13\\ \=xxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxx\=xxxxx\=xxxxx\=xxxxxxx\=\kill \>Type\> ID\> Adv Rtr\> Seq\> Age\> Opt\> Cksum\> Len\\ \=xxxxxxxx\=x\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxx\=xxxxx\=xxxxx\=xxxxxxx\=\kill \>Router\>*\> 192.150.187.112\> 192.150.187.112\> 0x80000001\> 1454\> 0x2\> 0x8a03\> 36\\ \>SummaryN\>*\>192.150.187.0\> 192.150.187.112\> 0x80000001\> 1443\> 0x2\> 0x4ef6\> 28\\ \>SummaryN\>*\>172.16.1.0\> 192.150.187.112\> 0x80000001\> 1453\> 0x2\> 0xa476\> 28\\ \>SummaryN\>*\>172.16.2.0\> 192.150.187.112\> 0x80000001\> 1453\> 0x2\> 0x9980\> 28\\ \>SummaryR\>*\>192.150.187.5\> 192.150.187.112\> 0x80000001\> 1443\> 0x2\> 0xbb4\> 28\\ \>ASExt-2\>\> 172.16.0.0\> 192.150.187.5\> 0x800003a9\> 990\> 0x2\> 0x77c1\> 36\\ OSPF link state database, Area 0.0.0.2\\ \=xxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxx\=xxxxx\=xxxxx\=xxxxxxx\=\kill \>Type\> ID\> Adv Rtr\> Seq\> Age\> Opt\> Cksum\> Len\\ \=xxxxxxxx\=x\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxx\=xxxxx\=xxxxx\=xxxxxxx\=\kill \>Router\>*\> 192.150.187.112\> 192.150.187.112\> 0x80000001\> 1454\> 0x2\> 0x93f8\> 36\\ \>SummaryN\>*\>192.150.187.0\> 192.150.187.112\> 0x80000001\> 1443\> 0x2\> 0x4ef6\> 28\\ \>SummaryN\>*\>172.16.0.0\> 192.150.187.112\> 0x80000001\> 1453\> 0x2\> 0xaf6c\> 28\\ \>SummaryN\>*\>172.16.2.0\> 192.150.187.112\> 0x80000001\> 1453\> 0x2\> 0x9980\> 28\\ \>SummaryR\>*\>192.150.187.5\> 192.150.187.112\> 0x80000001\> 1443\> 0x2\> 0xbb4\> 28\\ \>ASExt-2\>\> 172.16.0.0\> 192.150.187.5\> 0x800003a9\> 990\> 0x2\> 0x77c1\> 36\\ OSPF link state database, Area 0.0.0.3\\ \=xxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxx\=xxxxx\=xxxxx\=xxxxxxx\=\kill \>Type\> ID\> Adv Rtr\> Seq\> Age\> Opt\> Cksum\> Len\\ \=xxxxxxxx\=x\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxxxxxxxxx\=xxxxx\=xxxxx\=xxxxxxx\=\kill \>Router\>*\> 192.150.187.112\> 192.150.187.112\> 0x80000001\> 1454\> 0x2\> 0x9cee\> 36\\ \>SummaryN\>*\>192.150.187.0\> 192.150.187.112\> 0x80000001\> 1443\> 0x2\> 0x4ef6\> 28\\ \>SummaryN\>*\>172.16.0.0\> 192.150.187.112\> 0x80000001\> 1453\> 0x2\> 0xaf6c\> 28\\ \>SummaryN\>*\>172.16.1.0\> 192.150.187.112\> 0x80000001\> 1453\> 0x2\> 0xa476\> 28\\ \>SummaryR\>*\>192.150.187.5\> 192.150.187.112\> 0x80000001\> 1443\> 0x2\> 0xbb4\> 28\\ \>ASExt-2\>\> 172.16.0.0\> 192.150.187.5\> 0x800003a9\> 990\> 0x2\> 0x77c1\> 36\\ \end{tabbing} \end{alltt} \end{minipage} } The {\stt show ospf4 neighbor} command will show state of adjacencies: \vspace{0.1in} \noindent\framebox[\textwidth][l]{\scriptsize \begin{minipage}{6in} \begin{alltt} \begin{tabbing} user@hostname> show ospf4 neighbor\\ \=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxx\=\kill \> Address\> Interface\> State\> ID\> Pri\> Dead\\ \>192.150.187.5\> fxp0/fxp0\> Full\> 192.150.187.5\> 150\> 34\\ \>192.150.187.99\> fxp0/fxp0\> Full\> 192.150.187.99\> 128\> 34\\ \>192.150.187.108\> fxp0/fxp0\> TwoWay\> 192.150.187.108\> 128\> 34\\ \>192.150.187.78\> fxp0/fxp0\> Down\> 0.0.0.78\> 0\> 0\\ \end{tabbing} \end{alltt} \end{minipage} } \newpage The {\stt show ospf4 neighbor detail} command will show state of adjacencies with extra detail such as the Designated Router and the time the adjacency has been up: \vspace{0.1in} \noindent\framebox[\textwidth][l]{\scriptsize \begin{minipage}{6in} \begin{alltt} \begin{tabbing} user@hostname> show ospf4 neighbor detail\\ \=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxx\=\kill \> Address\> Interface\> State\> ID\> Pri\> Dead\\ \>192.150.187.5\> fxp0/fxp0\> Full\> 192.150.187.5\> 150\> 33\\ \=xxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxxxxx\=\kill \> Area 0.0.0.0,\> opt 0x2,\> DR 192.150.187.99,\> BDR 192.150.187.5\\ \> Up 54:09:26,\> adjacent 54:09:16\\ \=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxx\=\kill \>192.150.187.99\> fxp0/fxp0\> Full\> 192.150.187.99\> 128\> 38\\ \=xxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxxxxx\=\kill \> Area 0.0.0.0,\> opt 0x2,\> DR 192.150.187.99,\> BDR 192.150.187.5\\ \> Up 54:09:26,\> adjacent 54:09:16\\ \=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxx\=\kill \>192.150.187.108\> fxp0/fxp0\> TwoWay\> 192.150.187.108\> 128\> 33\\ \=xxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxxxxx\=\kill \> Area 0.0.0.0,\> opt 0x2,\> DR 192.150.187.99,\> BDR 192.150.187.5\\ \> Up 54:09:26\\ \=xxxxxxxxxxxxxxxx\=xxxxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxx\=xxxx\=\kill \>192.150.187.78\> fxp0/fxp0\> Down\> 0.0.0.78\> 0\> 0\\ \=xxxxxxxxxxxxxxxxxx\=xxxxxxxxx\=xxxxxxxxxxxxxxxxxxx\=\kill \> Area 0.0.0.0,\> opt 0,\> DR 0.0.0.0,\> BDR 0.0.0.0\\ \> Up 14:47:32\\ \end{tabbing} \end{alltt} \end{minipage} }