{"id":274,"date":"2015-01-07T09:22:26","date_gmt":"2015-01-07T09:22:26","guid":{"rendered":"http:\/\/feralpacket.org\/?p=274"},"modified":"2015-01-07T09:42:20","modified_gmt":"2015-01-07T09:42:20","slug":"ripv2-notes-3","status":"publish","type":"post","link":"https:\/\/feralpacket.org\/?p=274","title":{"rendered":"RIPv2 Notes"},"content":{"rendered":"

<\/p>\n

RIPv2<\/b><\/p>\n

– UDP port 520<\/p>\n

– Multicast IP 224.0.0.9<\/p>\n

– Classless (not by default)<\/p>\n

-> Cannot have discontiguous networks<\/p>\n

– Metric is hop count<\/p>\n

– Metric 16 is\u00a0\u00a0infinite\u00a0\u00a0metric<\/p>\n

– Timers<\/p>\n

-> Update timer: \u00a0\u00a030 seconds<\/p>\n

-> Invalid timer: \u00a0\u00a0180 seconds<\/p>\n

-> Holddown timer: \u00a0\u00a0180 seconds<\/p>\n

-> Flush timer: \u00a0\u00a0240 seconds<\/p>\n

– Supports authentication<\/p>\n

-> Plain text<\/p>\n

-> MD5<\/p>\n

– AD is 120<\/p>\n

 <\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0version 2<\/span><\/p>\n

\u00a0\u00a0no auto-summary<\/span><\/p>\n

\u00a0\u00a0network x.x.x.x<\/span><\/p>\n

 <\/p>\n

\"20141114_174326-1\"<\/a><\/p>\n

Mismatched version updates can cause one way communication between the routers<\/p>\n

– R1<\/p>\n

-> Send v1 updates<\/p>\n

-> Receive v1 and v2 updates<\/p>\n

– R2<\/p>\n

-> Send and receive v2 updates<\/p>\n

 <\/p>\n

Authentication<\/b><\/p>\n

– Plain text<\/p>\n

– MD5<\/p>\n

-> Create key chain<\/p>\n

-> Apply to an interface<\/p>\n

 <\/p>\n

key chain CISCO<\/span><\/p>\n

\u00a0\u00a0key 1<\/span><\/p>\n

\u00a0\u00a0 key-string CCIE<\/span><\/p>\n

 <\/p>\n

int s0\/0<\/span><\/p>\n

\u00a0\u00a0ip rip authentication mode { text | md5 }<\/span><\/p>\n

\u00a0\u00a0ip rip authentication key-chain CISCO<\/span><\/p>\n

 <\/p>\n

sh ip protocols<\/span><\/p>\n

– Lists the authentication method<\/p>\n

debug ip rip<\/span><\/p>\n

– To troubleshoot authentication problems<\/p>\n

-> Such as key mismatch<\/p>\n

sh key chain<\/span><\/p>\n

– To see if a space is present in the key-string<\/p>\n

 <\/p>\n

Summarization<\/b><\/p>\n

\"20141114_174332-1\"<\/a><\/p>\n

Summary address 10.0.0.0\/22<\/p>\n

 <\/p>\n

int fa0\/0<\/span><\/p>\n

\u00a0\u00a0ip rip summary-address 10.0.0.0 255.255.252.0<\/span><\/p>\n

 <\/p>\n

A summary address is installed into the routing table pointing to the NULL interface<\/p>\n

– Used when one of the more specific networks is not rachable<\/p>\n

– This prevents the packets from being default routed to 0.0.0.0\/0<\/p>\n

– Causes packets to be dropped<\/p>\n

– Summary address AS is still 120<\/p>\n

 <\/p>\n

RIP does not create a summary route pointing to NULL0<\/p>\n

– Must be created manually<\/p>\n

 <\/p>\n

ip route 10.0.0.0 255.255.252.0 NULL0<\/span><\/p>\n

 <\/p>\n

172.16.0.0 \/24<\/p>\n

172.16.1.0 \/24<\/p>\n

172.16.2.0 \/24<\/p>\n

172.16.3.0 \/24<\/p>\n

-> 172.16.0.0 \/22<\/p>\n

-> Works with RIPv2<\/p>\n

 <\/p>\n

172.0.0.0 \/16<\/p>\n

172.1.0.0 \/16<\/p>\n

172.2.0.0 \/16<\/p>\n

172.3.0.0 \/16<\/p>\n

-> 172.0.0.0 \/14<\/p>\n

-> Will not work with RIPv2<\/p>\n

-> Error message when trying to configure<\/p>\n

 <\/p>\n

RIPv2 summarization is only possible within the limits of a class (A, B, C)<\/p>\n

-> RIPv2 summarization is not classless<\/p>\n

 <\/p>\n

Default Routing<\/b><\/p>\n

\"20141114_174343-1\"<\/a><\/p>\n

R1(config)# router rip<\/span><\/p>\n

\u00a0\u00a0default-information originate<\/span><\/p>\n

 <\/p>\n

In other routing tables:<\/p>\n

 <\/p>\n

R* \u00a0\u00a00.0.0.0 \u00a0\u00a0\u00a0\u00a0 [120|*]<\/p>\n

-> The metric of the summary route is the least metric among more specific routes<\/p>\n

 <\/p>\n

Conditional Default Routing<\/b><\/p>\n

\"20141114_174353-1\"<\/a><\/p>\n

In conditional default routing, the exit interface network is checked<\/p>\n

– If the network is in the routing table, the default network will be injected<\/p>\n

– If the network is not in the routing table, the default route is not injected<\/p>\n

 <\/p>\n

R1(config)# access-list 1 permit 200.0.0.0 0.0.0.255<\/span><\/p>\n

route-map DR<\/span><\/p>\n

\u00a0\u00a0match ip address 1<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0default-information originate route-map DR<\/span><\/p>\n

 <\/p>\n

This is conditional, but not reliable<\/p>\n

– Have to make the route-map false to be reliable<\/p>\n

– Link may be up, but the connection to the Internet may be down<\/p>\n

 <\/p>\n

Reliable Conditional Default Routing<\/p>\n

– Uses IP SLA<\/p>\n

 <\/p>\n

Apply to RIP<\/p>\n

– IP SLA (Step 1) \u00a0<- -> \u00a0Track (Step 2) \u00a0<– Dummy Static Route (Step 3) \u00a0<– Access-list (Step 5) \u00a0<– Route-map (Step 5)<\/p>\n

 <\/p>\n

R1(config)# ip sla 1<\/span><\/p>\n

\u00a0\u00a0icmp-echo 4.2.2.2<\/span><\/p>\n

\u00a0\u00a0 timeout 2000<\/span><\/p>\n

-> In milliseconds<\/p>\n

frequency 4<\/span><\/p>\n

-> In seconds<\/p>\n

ip sla schedule 1 start-time now life forever<\/span><\/p>\n

track 1 ip sla 1 reachability<\/span><\/p>\n

ip route 169.254.0.0 255.255.0.0 NULL0 track 1<\/span><\/p>\n

access-list 1 permit 169.254.0.0 0.0.255.255<\/span><\/p>\n

route-map ABC<\/span><\/p>\n

\u00a0\u00a0match ip address 1<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0default-information originate route-map ABC<\/span><\/p>\n

 <\/p>\n

RIP Filtering<\/b><\/p>\n

\"20141114_174402-1\"<\/a><\/p>\n

Passive Interface<\/b><\/p>\n

– It stops sending updates out the specified interface<\/p>\n

 <\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0passive-interface { <interface> | default }<\/span><\/p>\n

 <\/p>\n

passive-interface default<\/span><\/p>\n

– Can be used if there are a lot of loopback interfaces that you do not want to advertise<\/p>\n

 <\/p>\n

Distribute List<\/b><\/p>\n

– Which network to filter<\/p>\n

– Direction ( in | out )<\/p>\n

– In | out which interface<\/p>\n

-> If not specified, the network will be filtered from all interfaces<\/p>\n

– Filter is outsourced!<\/p>\n

-> ACL<\/p>\n

-> Prefix-list<\/p>\n

 <\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0distribute-list in | out int <\/span><\/p>\n

 <\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0distribute-list prefix in | out int<\/span><\/p>\n

 <\/p>\n

 <\/p>\n

\"20141114_174409-1\"<\/a><\/p>\n

Distribute List – Standard ACL<\/b><\/p>\n

 <\/p>\n

access-list 1 deny 1.1.1.1<\/span><\/p>\n

access-list 1 permit any<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0distribute-list 1 out fa0\/0<\/span><\/p>\n

\"20141114_174413-1\"<\/a><\/p>\n

Scenario -> Filter all even number octets (in the 3rd octet) of outgoing network<\/p>\n

 <\/p>\n

255.255.11111110.255<\/p>\n

-> I don’t care about the first 7 bits, I only care about the last bit<\/p>\n

-> Subnet mask: \u00a0\u00a0255.255.254.255<\/p>\n

-> Wild card mask: \u00a0\u00a00.0.1.0<\/p>\n

 <\/p>\n

10.0.0.0 – 00000000<\/p>\n

10.0.2.0 – 00000010<\/p>\n

-> Last bit doesn’t change<\/p>\n

-> 0 – don’t care<\/p>\n

-> 1 – do care<\/p>\n

 <\/p>\n

access-list 1 deny 0.0.0.0 255.255.254.255<\/span><\/p>\n

access-list 1 permit any<\/span><\/p>\n

 <\/p>\n

– or –<\/p>\n

 <\/p>\n

access-list 1 permit 0.0.1.0 255.255.254.255<\/span><\/p>\n

 <\/p>\n

Distribute List – Extended ACL<\/b><\/p>\n

 <\/p>\n

access-list <number> permit | deny <protocol> <source> <destination><\/span><\/p>\n

– Protocol is ip<\/p>\n

– Source is update source<\/p>\n

– Destination is update network<\/p>\n

 <\/p>\n

\"20141114_174426-1\"<\/a><\/p>\n

Scenario -> On R1, filter incoming update for network 50.0.0.0 if it is coming from R3<\/p>\n

 <\/p>\n

R1(config)# access-list 100 deny ip host 123.0.0.3 host 50.0.0.0<\/span><\/p>\n

access-list 100 permit ip any any<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0distribute-list 100 in<\/span><\/p>\n

 <\/p>\n

Prefix Lists<\/b><\/p>\n

– More flexible<\/p>\n

– Can match on subnet masks<\/p>\n

 <\/p>\n

ip prefix-list <name> [seq <number>] permit | deny <network\/wildcard mask> [le | ge <0 – 32>]<\/span><\/p>\n

– <network\/wildcard mask> – prefix<\/p>\n

 <\/p>\n

– le | ge – subnet mask<\/p>\n

access-list <number> permit | deny <network> <wildcard mask><\/span><\/p>\n

 <\/p>\n

10.0.0.0 0.255.255.255<\/p>\n

 <\/p>\n

10.0.0.0 \/22<\/p>\n

10.0.0.0 \/24<\/p>\n

 <\/p>\n

ip prefix-list LIST1 deny 10.0.0.0\/8 ge 24 le 24<\/span><\/p>\n

– Matches 10.0.0.0 \/24<\/p>\n

 <\/p>\n

Match any network starting with 172.16.x.x with subnet mask from 255.255.0.0 to 255.255.255.0<\/p>\n

 <\/p>\n

255.255.0.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/16<\/p>\n

255.255.128.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/17<\/p>\n

255.255.192.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/18<\/p>\n

255.255.224.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/19<\/p>\n

255.255.240.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/20<\/p>\n

255.255.248.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/21<\/p>\n

255.255.252.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/22<\/p>\n

255.255.254.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/23<\/p>\n

255.255.255.0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-> \/24<\/p>\n

 <\/p>\n

ip prefix-list ABC deny 172.16.0.0\/16 ge 16 le 24<\/span><\/p>\n

 <\/p>\n

\"20141114_174436-1\"<\/a><\/p>\n

1.<\/p>\n

– Wildcard ->16<\/p>\n

– Range -> 16 – 24<\/p>\n

2.<\/p>\n

– Wildcard -> 16<\/p>\n

– Range -> 18 – 32<\/p>\n

-> If on the exam, upper boundary is not specific, assume it’s 32<\/p>\n

3.<\/p>\n

– Wildcard -> 16<\/p>\n

– Range -> 18 – 24<\/p>\n

 <\/p>\n

ip prefix-list ABC deny 172.16.0.0\/16 ge 18<\/span><\/p>\n

ip prefix-list ABC deny 172.16.0.0\/16 ge 18 le 24<\/span><\/p>\n

 <\/p>\n

Drawback of using prefix-lists<\/p>\n

– ge cannot be lower than the wildcard mask<\/p>\n

 <\/p>\n

Scenario -> Match any network starting with 172.16.0.0 and subnet mask between 8 and 24<\/p>\n

 <\/p>\n

ip prefix-list ABC deny 172.16.0.0\/16 ge 8 le 24<\/span><\/p>\n

-> Will not work<\/b><\/p>\n

-> ge cannot be lower than the wildcard mask<\/p>\n

 <\/p>\n

If a single subnet mask is to be matched and it happens to be equal to the wildcard mask, then ge and le can be skipped<\/p>\n

– Compare first octet of 10.0.0.0 and subnet mask must be 255.0.0.0<\/p>\n

 <\/p>\n

ip prefix-list permit 10.0.0.0\/8<\/span><\/p>\n

 <\/p>\n

\"20141114_174443-1\"<\/a><\/p>\n

Filter 1.1.1.1 \/32 from R2<\/p>\n

 <\/p>\n

R1(config)# ip prefix-list ABC deny 1.1.1.1\/32<\/span><\/p>\n

\u00a0\u00a0ip prefix-list ABC permit 0.0.0.0\/0 le 32<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0distribute-list prefix ABC out fa0\/0<\/span><\/p>\n

 <\/p>\n

Filter from a specific source<\/b><\/p>\n

\"20141114_174452-1\"<\/a><\/p>\n

Scenario -> Filter any network coming from R3 and accept all networks from R2<\/p>\n

– In this scenario, two prefix lists will be used<\/p>\n

-> 1. To identify which networks will be filtered<\/p>\n

-> 2. To identify the source<\/p>\n

 <\/p>\n

Distribute List<\/b><\/p>\n

 <\/p>\n

distribute-list prefix <list1> gateway <list2> in | out [<interface>]<\/span><\/p>\n

 <\/p>\n

R1(config)# ip prefix-list LIST1 permit 50.0.0.0\/8<\/span><\/p>\n

\u00a0\u00a0ip prefix-list LIST2 deny 123.0.0.3\/32<\/span><\/p>\n

\u00a0\u00a0ip prefix-list LIST2 permit 123.0.0.2\/32<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0distribute-list prefix LIST1 gateway LIST2 in fa0\/0<\/span><\/p>\n

 <\/p>\n

During the lab, always use extended ACLs unless using prefix-lists is spcified<\/p>\n

 <\/p>\n

sh ip protocols<\/span><\/p>\n

– Displays the distribute-lists applied<\/p>\n

 <\/p>\n

Offset-list<\/b><\/p>\n

– This is used to add an offset number to the metric value when updates are sent or received<\/p>\n

\"20141114_174500-1\"<\/a><\/p>\n

Scenario -> R1 should always use R2 as next-hop to reach network x (50.0.0.0)<\/p>\n

– If connection to R2 goes down, R1 should start using R3 as next-hop for network x<\/p>\n

 <\/p>\n

offset-list <acl> in | out <offset-number> [<interface>]<\/span><\/p>\n

– Standard ACL is used<\/p>\n

access-list 1 permit 50.0.0.0<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0offset-list 1 in 2 s0\/1<\/span><\/p>\n

 <\/p>\n

For filtering purposes, offset number 16 can be used<\/p>\n

 <\/p>\n

Scenario -> Filter all network from R3<\/p>\n

 <\/p>\n

access-list 1 permit any<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0offset 1 in 16 s0\/1<\/span><\/p>\n

 <\/p>\n

– or –<\/p>\n

 <\/p>\n

! No ACL needed<\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0offset-list 0 in 16 s0\/1<\/span><\/p>\n

 <\/p>\n

Filtering By Manipulating AD<\/b><\/p>\n

– AD 255<\/p>\n

-> Unreachable<\/p>\n

-> Route deleted from the routing table<\/p>\n

 <\/p>\n

Scenario -> Filter network 50.0.0.0 from any router<\/p>\n

 <\/p>\n

access-list 1 permit 50.0.0.0<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0distance 255 0.0.0.0 255.255.255.255 1<\/span><\/p>\n

-> 0.0.0.0 255.255.255.255 – the source<\/p>\n

-> 1 – ACL<\/p>\n

 <\/p>\n

Scenario -> Filter 50.0.0.0 from R3 (123.0.0.3)<\/p>\n

 <\/p>\n

access-list 1 permit 50.0.0.0<\/span><\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0distance 255 123.0.0.3 0.0.0.0 1<\/span><\/p>\n

 <\/p>\n

RIP Miscellaneous Topics<\/b><\/p>\n

– Change timers<\/p>\n

– Unicast updates<\/p>\n

– Triggered updates<\/p>\n

– Send \/ receive version<\/p>\n

 <\/p>\n

Changing Timers<\/b><\/p>\n

– rip configation<\/p>\n

– inside interface<\/p>\n

 <\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0timers basic<\/span><\/p>\n

 <\/p>\n

 <\/p>\n

int fa0\/0<\/span><\/p>\n

\u00a0\u00a0ip rip advertise<\/span><\/p>\n

 <\/p>\n

 <\/p>\n

\"20141114_174512-1\"<\/a><\/p>\n

Scenario -> Change the RIP timers to 20, 90, 90, 120, but keep the update time to 30 seconds for fa0\/0<\/p>\n

 <\/p>\n

R1(config)# router rip<\/span><\/p>\n

\u00a0\u00a0timers basic 20 90 90 120<\/span><\/p>\n

int fa0\/0<\/span><\/p>\n

\u00a0\u00a0ip rip advertise 30<\/span><\/p>\n

 <\/p>\n

Unicast Updates<\/b><\/p>\n

\"20141114_174518-1\"<\/a><\/p>\n

To switch to unicast updates<\/p>\n

– Stop sending multicast updates<\/p>\n

– Start sending unicast updates<\/p>\n

 <\/p>\n

On R1 \/ R2:<\/p>\n

 <\/p>\n

router rip<\/span><\/p>\n

\u00a0\u00a0passive-interface fa0\/0<\/span><\/p>\n

\u00a0\u00a0neighbor 12.0.0.x<\/span><\/p>\n

 <\/p>\n

Triggered Updates<\/b><\/p>\n

– Any serial (point-to-point) interface the periodic updates can be disabled and made triggered<\/p>\n

\"20141114_174525-1\"<\/a><\/p>\n

On R1 \/ R2:<\/p>\n

 <\/p>\n

int s0\/0<\/span><\/p>\n

\u00a0\u00a0ip rip triggered<\/span><\/p>\n

 <\/p>\n

debug ip rip<\/span><\/p>\n

sh ip protocols<\/span><\/p>\n

 <\/p>\n

Send | Receive Version<\/p>\n

– By default if the version command is not used, then all interfaces<\/p>\n

-> Send v1 updates<\/p>\n

-> Receive v1 and v2 updates<\/p>\n

– If the version command is used, the interfaces will send and receive the version specified<\/p>\n

– The impact of the version command can be overridden by using interface specific commands<\/p>\n

 <\/p>\n

int fa0\/0<\/span><\/p>\n

\u00a0\u00a0ip rip send version { 1 | 2 }<\/span><\/p>\n

\u00a0\u00a0ip rip receive version { 1 | 2 }<\/span><\/p>\n

 <\/p>\n

sh ip protocols<\/span><\/p>\n

 <\/p>\n

router rip will not display in show run if a network statement is not configured<\/p>\n

ip rip advertise 30 will not show up in the sh run config because it is the default configuration<\/p>\n

– Use sh ip route to verify the proper networks are received on the interface<\/p>\n

 <\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

RIPv2 – UDP port 520 – Multicast IP 224.0.0.9 – Classless (not by default) -> Cannot have discontiguous networks – Metric is hop count – Metric 16 is\u00a0\u00a0infinite\u00a0\u00a0metric – Timers -> Update timer: \u00a0\u00a030 seconds -> Invalid timer: \u00a0\u00a0180 seconds -> Holddown timer: \u00a0\u00a0180 seconds -> Flush timer: \u00a0\u00a0240 seconds – Supports authentication -> Plain […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[30,21,26,10],"class_list":["post-274","post","type-post","status-publish","format-standard","hentry","category-ccie","tag-ccie","tag-rip","tag-ripv2","tag-service-provider"],"_links":{"self":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/274","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=274"}],"version-history":[{"count":6,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/274\/revisions"}],"predecessor-version":[{"id":280,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/274\/revisions\/280"}],"wp:attachment":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=274"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=274"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=274"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}