OSPF Multicast Routing update LSA

First, when the OSPF adjacency relationship is established, the DR and all devices are full,bdr with all devices for the full,drother between 2-way (DR and BDR are also full).

When OSPF routes are updated, DR/BDR monitors 224.0.0.5 and 224.0.0.6.

Drothe Monitor 224.0.0.5.

When the Drother route has an update, DR/BDR will receive it, but the flooding is sent to all devices by DR.

The following experiments all update to "new release route".

Second, topology information

650) this.width=650; "Src=" Http://s2.51cto.com/wyfs02/M00/83/D0/wKiom1d87lXS10-JAABOYMHRnGk217.png-wh_500x0-wm_3 -wmp_4-s_1280006883.png "title=" 01.png "alt=" Wkiom1d87lxs10-jaaboymhrngk217.png-wh_50 "/>

1, when the Drother routing update, to the multicast mode sent to 224.0.0.6 (that is, DR/BDR), because it is a multicast mode, all the packets caught in any router g0/0/0 interface received the same, the specific capture package is as follows:

650) this.width=650; "Src=" Http://s1.51cto.com/wyfs02/M01/83/D0/wKiom1d86wvwzxVNAAA6hSjzbf4017.png-wh_500x0-wm_3 -wmp_4-s_976781557.png "title=" Drother.png "alt=" Wkiom1d86wvwzxvnaaa6hsjzbf4017.png-wh_50 "/>

Drother send LS Update---------------> 224.0.0.6 (to DR/BDR)

Dr receives drother update after sending LS update-------------> 224.0.0.5 (All Drother)

Droter received Dr's LS Update-------------> 224.0.0.6 (Reply dr)

BDR received drother update LS update----------->224.0.0.5 (reply drother send updater?) ）

2. When the Dr Route is updated, multicast is sent to 224.0.0.5 (all devices, including BDR) because it is multicast, all packets caught in the g0/0/0 interface of any router receive the same, and the specific packet captures are as follows:

650) this.width=650; "Src=" Http://s2.51cto.com/wyfs02/M02/83/CE/wKioL1d86yKBjgzjAAAwfuo_4UQ900.png-wh_500x0-wm_3 -wmp_4-s_2945862754.png "title=" Dr.png "alt=" Wkiol1d86ykbjgzjaaawfuo_4uq900.png-wh_50 "/>

Dr sends LS Update---------------> 224.0.0.5 (for all devices)

Drother send LS ack after receiving update of Dr-------------> 224.0.0.6 (Reply dr)

BDR sends LS ack after receiving DR Update-------------> 224.0.0.5 (Reply dr? Because BDR also listens to 224.0.0.5)

3, when the BDR routing updates, multicast to send to 224.0.0.5 (all devices, including DR) because it is multicast, all the packets caught in any router g0/0/0 interface receive the same, the specific capture package is as follows:

650) this.width=650; "Src=" Http://s4.51cto.com/wyfs02/M02/83/D0/wKiom1d86zaB-1uWAAA-_k3tjI4341.png-wh_500x0-wm_3 -wmp_4-s_715959505.png "title=" Bdr.png "alt=" Wkiom1d86zab-1uwaaa-_k3tji4341.png-wh_50 "/>

BDR sends LS Update---------------> 224.0.0.5 (for all devices)

Drother send ls ack-------------> 224.0.0.6 (Reply dr) after receiving the update from BDR

Dr receives the update of BDR and sends LS ack-------------> 224.0.0.5 (Reply to BDR? Because Dr also listens to 224.0.0.5)

This article is from the "Five Corners" blog, please be sure to keep this source http://hi289.blog.51cto.com/4513812/1811621

OSPF Multicast Routing update LSA