{"id":694,"date":"2018-10-26T22:27:24","date_gmt":"2018-10-26T22:27:24","guid":{"rendered":"http:\/\/feralpacket.org\/?p=694"},"modified":"2018-10-26T22:27:24","modified_gmt":"2018-10-26T22:27:24","slug":"multicast-auto-rp-notes","status":"publish","type":"post","link":"https:\/\/feralpacket.org\/?p=694","title":{"rendered":"Multicast Auto-RP Notes"},"content":{"rendered":"

Multicast Auto-RP<\/span><\/p>\n

\u00a0– Cisco proprietary<\/p>\n

\u00a0– Uses a Mapping Agent (MA) to distribute RP information<\/p>\n

\u00a0– RP informs the MA about themselves<\/p>\n

\u00a0 \u00a0 \u00a0-> Announce message<\/p>\n

\u00a0– MA sends a Discovery message to all routes<\/p>\n

\u00a0– Announce message are multicast messages sent by RPs to the destination<\/p>\n

\u00a0 \u00a0 \u00a0-> 224.0.1.39, UDP port 496<\/p>\n

\u00a0 \u00a0 \u00a0-> Only MAs join the group and will receive the message<\/p>\n

\u00a0– Discovery messages are multicast messages sentby the MA to<\/p>\n

\u00a0 \u00a0 \u00a0-> 224.0.1.40, UDP port 496<\/p>\n

\u00a0 \u00a0 \u00a0-> All routers join this group and will receive the message<\/p>\n

\u00a0– If multiple RPs exist, only the higher IP address RP information is sent by the MA<\/p>\n

\u00a0– The election of a specific RP is done only if all RPs are claiming to service the same group range<\/p>\n

\u00a0 \u00a0 \u00a0-> 224.0.0.0\/4<\/p>\n

\u00a0– If RPs are claiming the service groups, then MA sends the information of all RPs to everyone<\/p>\n

e.g. –<\/p>\n

R2 -> 224.0.0.0 – 231.255.255.255<\/p>\n

R3 -> 232.0.0.0 – 239.255.255.255<\/p>\n

\u00a0 \u00a0 \u00a0-> Both RPs will be used<\/p>\n

Scenario – R2 (2.2.2.2) -> 224.0.0.0 – 235.255.255.255<\/p>\n

R3 (3.3.3.3) -> 232.0.0.0 – 239.255.255.255<\/p>\n

\u00a0 \u00a0 \u00a0-> Overlapping range<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> 232.0.0.0 – 235.255.255.255<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> R3 will be used for the RP because of the higher IP address<\/p>\n

If multiple RPs are claiming the same range with different prefix-lengths, then the longest matching prefix will be used<\/p>\n

<\/p>\n

Configuring the RP<\/span><\/p>\n

ip pim send-rp-announce <int> scope <ttl> [group-list <acl>] [interval <sec>]<\/span><\/p>\n

\u00a0– The interval default is 60 seconds<\/p>\n

\u00a0– If group-list is not definded, the RP will claim to serve all multicast IP addresses<\/p>\n

Configuring the MA<\/span><\/p>\n

ip pim send-rp-discovery <int> scope <ttl> [interval <sec>]<\/span><\/p>\n

\u00a0<\/p>\n

\u00a0– The interval default is 60 seconds<\/p>\n

R2(config)#\u00a0access-list 1 permit 224.0.0.0 7.255.255.255<\/span><\/p>\n

R3(config)#\u00a0access-list 1 permit 224.0.0.0 15.255.255.255<\/span><\/p>\n

\u00a0access-list 1 permit 224.0.0.0 15.255.255.255<\/span><\/p>\n

\u00a0 \u00a0 \u00a0-> This ACL covers the entire multicast IP address range<\/p>\n

On any router<\/p>\n

sh ip pim rp mapping<\/span><\/p>\n

Configuring Auto-RP<\/p>\n

\u00a01. Activate multicast routing<\/p>\n

\u00a02. Configure PIM sparse mode on all interfaces<\/p>\n

\u00a03. Configure RP and MA<\/p>\n

Join messages have to be sent to<\/p>\n

\u00a0– Accounce -> 224.0.1.39<\/p>\n

\u00a0– Discovery – 224.0.1.40<\/p>\n

\u00a0– Problem<\/p>\n

\u00a0 \u00a0 \u00a0-> The router cannot join without knowing where to send the join messages<\/p>\n

\u00a0 \u00a0 \u00a0-> The links are pruned<\/p>\n

\u00a0 \u00a0 \u00a0-> This means that announce and discovery messages cannot be sent by default<\/p>\n

\u00a0– Solution<\/p>\n

\u00a0 \u00a0 \u00a0-> Send messages in dense mode and flood the messages<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Change all ports to sparse-dense-mode<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 – or –<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 -> Use sparse-mode and configure all routers with\u00a0ip pim autorp listener<\/span><\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0-> This commands converts the annouce and discovery groups to dense mode<\/p>\n","protected":false},"excerpt":{"rendered":"

Multicast Auto-RP<\/p>\n","protected":false},"author":1,"featured_media":693,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[54,46,31],"class_list":["post-694","post","type-post","status-publish","format-standard","hentry","category-ccie","tag-auto-rp","tag-multicast","tag-published"],"_links":{"self":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/694","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=694"}],"version-history":[{"count":1,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/694\/revisions"}],"predecessor-version":[{"id":701,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/posts\/694\/revisions\/701"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=\/wp\/v2\/media\/693"}],"wp:attachment":[{"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=694"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=694"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/feralpacket.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=694"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}