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Showing posts from 2012

PIM Overview

In this post we will try to have an overview of PIM PIM (Protocol Independent Multicast) is a protocol to carry multicast traffic, as the name indicates (Protocol Independent) PIM doesn’t have topology discovery built-in mechanisms, PIM relies on the unicast routing protocol to build the Multicast trees. PIM comes in 4 modes PIM-DENSE: implicit join, i.e the multicast traffic is flooded everywhere and then pruned from receivers that don’t want to receive this specific feed PIM-SPARSE: explicit join, senders register with RP (Rendvous Point) and receivers contact RP routers to receive specific multicast feeds when needed PIM-BiDirectional: doesn’t build SPT (shortest Path Tree) and doesn’t maintain (S,G) entries PIM-Source Specific Multicast: Source Specific Multicast method allows clients to choose the source of multicast feed. It requires IGMP version 3 though. SSM builds SPT tree and does not require RP to operate. PIM maintains neighbour ship relation using hello messages (sent to

IPv6 redistribution

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IPv6 redistribution is almost identical to the IPv4 version, expect IPv6 redistribution doesn’t include the connected interfaces by default In the above topology, the setup is quite simple R1-R2 are running RIP and R1-R3 are running OSPFv3 Configurations R1 interface Loopback0   ipv6 address 2001:1:1::1/64   ipv6 rip RIP enable ! interface FastEthernet0/0   ipv6 address FE80::1 link-local   ipv6 address FC00:12:12::1/64   ipv6 rip RIP enable R2 interface Loopback0   ipv6 address 2001:2:2::2/64   ipv6 rip RIP enable ! interface FastEthernet0/0   ipv6 address FE80::2 link-local   ipv6 address FC00:12:12::2/64   ipv6 rip RIP enable ! interface FastEthernet0/1   ipv6 address FE80::2 link-local   ipv6 address FC00:23:23::2/64   ipv6 ospf 1 area 0 ! ipv6 router ospf 1   router-id 2.2.2.2 R3 interface Loopback0   ipv6 address 2001:3:3::3/64   ipv6 ospf 1 area 0 ! interface FastEthernet0/0   ipv6 address FE80::3 link-local   ipv6 address FC00:23:23::3/64   ipv6 ospf 1 a

IPv6 Static Routes

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This just a simple setup to show static routes in IPv6, R1 ipv6 unicast-routing interface FastEthernet0/0 ipv6 address FC00:1:12:12::1/64 R2 ipv6 unicast-routing interface FastEthernet0/0 ipv6 address FC00:1:12:12::1/64 interface lo0 ipv6 address 2001:2:22:22:: 2/64   We will then configure IPv6 default static route from R1 to R2 to reach the loopback of R2 but instead of pointing it to the IPv6 address of R2 f0/0 we will use f0/0 of R1 on R1 R1(config)#ipv6 route ::/0 FastEthernet0/0 now let’s try to ping R2 loopback interface R1(config)#do p 2001:2:22:22::2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 2001:2:22:22::2, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) As we can see ping is failing, let’s debug IPv6 packets on R1 R1#debug ipv6 packet IPv6 unicast packet debugging is on R1#p 2001:2:22:22::2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 200

IPv6–OSPVv3

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OSPFv3 is very similar to OSPFv2, configuration wise is almost identical similar to IPv6 EIGRP the router-id is in 32 bits format, in our setup we have 3 areas, and because area 34 is not connected to backbone area  we need to configure a virtual link in area 23 to connect area 34 to the backbone configurations is the same except one caveat that we will try to explore in this post shortly R1 interface Loopback0   no ip address   ipv6 address 2001:1:1::1/64   ipv6 ospf 1 area 0 ! interface FastEthernet0/0   ipv6 enable   ipv6 ospf 1 area 0 ! ! ipv6 router ospf 1   router-id 1.1.1.1 R2 interface FastEthernet0/0   ipv6 enable   ipv6 ospf 1 area 0 ! interface FastEthernet0/1   ipv6 enable   ipv6 ospf 1 area 23 ! ! ipv6 router ospf 1   router-id 2.2.2.2 R3 interface loopback 0 ipv6 address 2001:3:33::3/64 ! interface FastEthernet0/10   ipv6 enable   ipv6 ospf 1 area 23 ! interface FastEthernet0/1   ipv6 enable   ipv6 ospf 1 area 34 ! ! ipv6 router ospf 1   router-id

IPv6 –Tunnelling

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There are many ways of transporting IPv6 over IPv4 networks, one of these methods is tunnelling, Tunnelling is simply encapsulating IPv6 packets within the tunnel so they appear as IPv4 packets on the tunnel ends In this post we will see types of tunnels, GRE (Generic Routing Encapsulation) and IPv6 in IPv4 tunnels GRE Tunnels can carry any type of traffic including IPv6 IPv6 in IPv4 Tunnels: are only designed to carry IPv6 traffic only In the network that we have in this post, we have IPv4 network between R1, R2 and R3 and the three routers are running IPv6 on their LAN networks with R4, R5 and R6 respectively. within the IPv4 network we will run an IGP, I am using OSPF in this post but any other protocol can be used including static routes Configurations R1 ipv6 unicast-routing ! interface Loopback0   ip address 1.1.1.1 255.255.255.255   ip ospf 1 area 0 ! interface FastEthernet0/0   ip address 10.1.123.1 255.255.255.0   ip ospf 1 area 0 interface FastEthernet0/1   ipv6

IPv6–RIPNG

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In this post we will try to explore various  RIPng configuration, RIPng on broadcast networks and NBMA networks, routes filtering, summarization and default route injection into RIPng Basic configuration R1: ipv6 unicast-routing interface Loopback100   no ip address   ipv6 address FC00:1:145:1::1/64 ! interface FastEthernet0/0   ipv6 enable interface Serial1/0   encapsulation frame-relay   ipv6 enable R2 ipv6 unicast-routing interface Loopback100   no ip address   ipv6 address FC00:1:123:2::2/64 interface Serial1/0   no ip address   encapsulation frame-relay   ipv6 enable   R3 ipv6 unicast-routing interface Loopback100   ipv6 address FC00:1:123:3::3/64 interface Serial1/0   encapsulation frame-relay   ipv6 enable R4 ipv6 unicast-routing ! interface Loopback100   no ip address   ipv6 address FC00:1:145:4::4/64 ! interface FastEthernet0/0   ipv6 enable R5 ipv6 unicast-routing ! interface Loopback100   no ip address   ipv6 address FC00:1:145:5::5/64 !