ISIS on Huawei routers ISIS is
a link-state IGP protocol. It gathers routing information from adjacent neighbors and uses the SPF algorithm to determine the best paths to destinations. I wouldn’t like to focus on the theory because you can find it in m any sources. Let’s configure ISIS protocol based on the following topology
!onfigure IP addresses of physical and loopback interfaces on all routers "it is omitted here# <1> dis ip interface brief Interface Ethernet0/0/8 LoopBack0
IP Address/Mask 10.0.0.1/30 1.1.1.1/32
Physical up up
Protocol up up(s)
IP Address/Mask 10.0.0.2/30 20.0.0.1/30 10.0.2.2/30 2.2.2.2/32
Physical up up up up
Protocol up up up up(s)
IP Address/Mask 10.0.2.1/30 30.0.0.1/30 3.3.3.3/32
Physical up up up
Protocol up up up(s)
IP Address/Mask 40.0.0.1/30 20.0.0.2/30 30.0.0.2/30 4.4.4.4/32
Physical up up up up
Protocol up up up up(s)
IP Address/Mask 40.0.0.2/30 5.5.5.5/32
Physical up up
Protocol up up(s)
<2> dis ip interface brief Interface Ethernet2/0/0 GigabitEthernet0/0/0 GigabitEtherne t0/0/0 GigabitEthernet0/0/1 GigabitEtherne t0/0/1 LoopBack0 <3> dis ip interface brief Interface GigabitEthernet0/0/0 GigabitEtherne t0/0/0 GigabitEthernet0/0/1 GigabitEtherne t0/0/1 LoopBack0 <4> dis ip interface br Interface Ethernet4/0/0 GigabitEthernet0/0/0 GigabitEtherne t0/0/0 GigabitEthernet0/0/1 GigabitEtherne t0/0/1 LoopBack0 <5> dis ip interface brief Interface Ethernet0/0/8 LoopBack0
!onfigure ISIS globally$ on loopback and physical interfaces "router % as an e&le# [2]isis [2] isis [2-isis-1]network-entity [2-isis-1]network-entity 10.0020.0200.2002.00 [2]interface LoopBack 0 [2-LoopBack0]isis [2-LoopBack0]isis enable [2]interface Ethernet2/0/0 [2-Ethernet2/0/0]isis [2-Ethernet2/0/0] isis enable [2]interface GigabitEthernet0/0/0 [2-GigabitEthernet0/0/0]isis [2-GigabitEthernet0/0/0] isis enable [2]interface GigabitEthernet0/0/1 [2-GigabitEthernet0/0/1]isis [2-GigabitEthernet0/0/1] isis enable
It should be noted at this point that routers '$ % and ( are in area ') and routers * and + in area %). ,dditionally you should remember about hierarchical structure of ISIS. In our case router ' works as leel-'$ routers % and ( work as leel-'-% "by default# and routers * and + as leel-%. Leel-' is an euialent of the stub area in /SPF. Leel-' routers hae only a defult route to e&ternal destinations. [1]isis [1-isis-1]is-level level-1 [2]isis [2-isis-1]is-level level-1-2 [3]isis [3-isis-1]is-level level-1-2 [4]isis [4-isis-1]is-level level-2 [5]isis [5-isis-1]is-level level-2
Let’s erify this configuration [1]display isis lsdb Database information for ISIS(1) -------------------------------Level-1 Link State Database LSPID Seq Num Checksum Holdtime Length ATT/P/OL ------------------------------------------------------------------------------0010.0100.1001.00-00* 0010.0100.1001 .00-00* 0x0000000d 0x936 667 84 0/0/0 0020.0200.2002.00-00 0020.0200.2002 .00-00 0x00000013 0x5d55 705 127 1/0/0 0020.0200.2002.02-00 0020.0200.2002 .02-00 0x00000009 0xb1e5 705 55 0/0/0 0020.0200.2002.03-00 0020.0200.2002 .03-00 0x00000009 0xd901 705 55 0/0/0 0030.0300.3003.00-00 0030.0300.3003 .00-00 0x00000010 0x699b 596 100 1/0/0
0020.0200.2002 .02 02--00
))%).)%)).%))% - source I0 )% - pseudonode I0 )) - LSP number Leel-' router • • •
has the link state information of the local area finds the nearest leel '-% router based on ,11 bit of the LSP generates a default route through the nearest leel-'-% router to isit the destinations outside this area.
[2]display isis lsdb Database information for ISIS(1) -------------------------------Level-1 Link State Database LSPID Seq Num Checksum Holdtime Length ATT/P/OL ------------------------------------------------------------------------------0010.0100.1001.00-00 0010.0100.1001 .00-00 0x0000000e 0x737 1030 84 0/0/0 0020.0200.2002.00-00* 0020.0200.2002 .00-00* 0x00000014 0x5b56 1087 127 1/0/0 0020.0200.2002.02-00* 0020.0200.2002 .02-00* 0x0000000a 0xafe6 1087 55 0/0/0 0020.0200.2002.03-00* 0020.0200.2002 .03-00* 0x0000000a 0xd702 1087 55 0/0/0 0030.0300.3003.00-00 0030.0300.3003 .00-00 0x00000011 0x679c 931 100 1/0/0 Level-2 Link State Database LSPID Seq Num Checksum Holdtime Length ATT/P/OL ------------------------------------------------------------------------------0020.0200.2002.00-00* 0020.0200.2002 .00-00* 0x00000016 0xdb0 1087 163 0/0/0 0020.0200.2002.01-00* 0020.0200.2002 .01-00* 0x0000000a 0x1f56 1086 55 0/0/0 0020.0200.2002.02-00* 0020.0200.2002 .02-00* 0x0000000a 0xafe6 1086 55 0/0/0 0030.0300.3003.00-00 0030.0300.3003 .00-00 0x00000014 0x6801 930 159 0/0/0 0030.0300.3003.02-00 0030.0300.3003 .02-00 0x0000000a 0xa48b 930 55 0/0/0 0040.0400.4004.00-00 0040.0400.4004 .00-00 0x00000010 0x5165 434 138 0/0/0 0040.0400.4004.03-00 0040.0400.4004 .03-00 0x00000009 0x9435 434 55 0/0/0 0050.0500.5005.00-00 0050.0500.5005 .00-00 0x0000000d 0xaa58 985 84 0/0/0
Leel-'-% router • • • •
forms adjacency with both leel-'-% and leel-% routers contains both leel-' and leel-% LS02s sets ,11 bit in the leel-' LSP originated by itself contains routing information of the whole network.
[4]display isis lsdb Database information for ISIS(1) -------------------------------Level-2 Link State Database LSPID Seq Num Checksum Holdtime Length ATT/P/OL ------------------------------------------------------------------------------0020.0200.2002.00-00 0020.0200.2002 .00-00 0x00000016 0xdb0 1034 163 0/0/0 0020.0200.2002.01-00 0020.0200.2002 .01-00 0x0000000a 0x1f56 1034 55 0/0/0 0 /0/0 0020.0200.2002.02-00 0020.0200.2002 .02-00 0x0000000a 0xafe6 1034 55 0/0/0 0 /0/0 0030.0300.3003.00-00 0030.0300.3003 .00-00 0x00000014 0x6801 880 159 0/0/0 0030.0300.3003.02-00 0030.0300.3003 .02-00 0x0000000a 0xa48b 880 55 0/0/0 0040.0400.4004.00-00* 0040.0400.4004 .00-00* 0x00000010 0x5165 385 138 0/0/0 0040.0400.4004.03-00* 0040.0400.4004 .03-00* 0x00000009 0x9435 385 55 0/0/0 0 /0/0 0050.0500.5005.00-00 0050.0500.5005 .00-00 0x0000000d 0xaa58 936 84 0/0/0
Leel-% router • • •
forms adjacency with both leel-% and leel-'-% routers gathers LSPs of all routers in backbone area contains all routing information of the whole routing domain.
Let’s look at ISIS routing tables [1]dis isis route Route information for ISIS(1) ----------------------------ISIS(1) Level-1 Forwarding Table --------------------------------
IPV4 Destination IntCost ExtCost E xtCost ExitInterface NextHop Flags ------------------------------------------------------------------------------0.0.0.0/0 10 NULL Eth0/0/8 10.0.0.2 A/-/-/10.0.0.0/30 10 NULL Eth0/0/8 Direct D/-/L/20.0.0.0/30 20 NULL Eth0/0/8 10.0.0.2 A/-/-/30.0.0.0/30 30 NULL Eth0/0/8 10.0.0.2 A/-/-/3.3.3.3/32 20 NULL Eth0/0/8 10.0.0.2 A/-/-/2.2.2.2/32 10 NULL Eth0/0/8 10.0.0.2 A/-/-/10.0.2.0/30 20 NULL Eth0/0/8 10.0.0.2 A/-/-/1.1.1.1/32 0 NULL Loop0 Direct D/-/L/Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut, U-Up/Down Bit Set
, default route must e&ist in the Leel-' routing table and the ne&t hop is a Leel-'-% router. [2]dis isis route Route information for ISIS(1) ----------------------------ISIS(1) Level-1 Forwarding Table -------------------------------IPV4 Destination IntCost ExtCost E xtCost ExitInterface NextHop Flags ------------------------------------------------------------------------------0.0.0.0/0 10 NULL 10.0.0.0/30 10 NULL Eth2/0/0 Direct D/-/L/20.0.0.0/30 10 NULL GE0/0/0 Direct D/-/L/30.0.0.0/30 20 NULL GE0/0/1 10.0.2.1 A/-/L/3.3.3.3/32 10 NULL GE0/0/1 10.0.2.1 A/-/L/2.2.2.2/32 0 NULL Loop0 Direct D/-/L/10.0.2.0/30 10 NULL GE0/0/1 Direct D/-/L/1.1.1.1/32 10 NULL Eth2/0/0 10.0.0.1 A/-/L/Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut, U-Up/Down Bit Set ISIS(1) Level-2 Forwarding Table -------------------------------IPV4 Destination IntCost ExtCost E xtCost ExitInterface NextHop Flags ------------------------------------------------------------------------------10.0.0.0/30 10 NULL Eth2/0/0 Direct D/-/L/20.0.0.0/30 10 NULL GE0/0/0 Direct D/-/L/30.0.0.0/30 20 NULL 40.0.0.0/30 20 NULL GE0/0/0 20.0.0.2 A/-/-/3.3.3.3/32 10 NULL 2.2.2.2/32 0 NULL Loop0 Direct D/-/L/10.0.2.0/30 10 NULL GE0/0/1 Direct D/-/L/5.5.5.5/32 20 NULL GE0/0/0 20.0.0.2 A/-/-/1.1.1.1/32 30 NULL 4.4.4.4/32 10 NULL GE0/0/0 20.0.0.2 A/-/-/Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut, U-Up/Down Bit Set
Leel-'-% routers contain both leel-' and leel-% routing tables. [5]dis isis route Route information for ISIS(1) ----------------------------ISIS(1) Level-2 Forwarding Table -------------------------------IPV4 Destination IntCost ExtCost E xtCost ExitInterface NextHop Flags ------------------------------------------------------------------------------10.0.0.0/30 30 NULL Eth0/0/8 40.0.0.1 A/-/-/20.0.0.0/30 20 NULL Eth0/0/8 40.0.0.1 A/-/-/30.0.0.0/30 20 NULL Eth0/0/8 40.0.0.1 A/-/-/40.0.0.0/30 10 NULL Eth0/0/8 Direct D/-/L/3.3.3.3/32 20 NULL Eth0/0/8 40.0.0.1 A/-/-/2.2.2.2/32 20 NULL Eth0/0/8 40.0.0.1 A/-/-/10.0.2.0/30 30 NULL Eth0/0/8 40.0.0.1 A/-/-/-
5.5.5.5/32 0 NULL Loop0 Direct D/-/L/1.1.1.1/32 30 NULL Eth0/0/8 40.0.0.1 A/-/-/4.4.4.4/32 10 NULL Eth0/0/8 40.0.0.1 A/-/-/Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut, U-Up/Down Bit Set
, Leel-% router must hae all Leel-' and Leel-% routes. 3e can see it better in IP routing t ables [1]display ip routing-table [1]display Route Flags: R - relay, D - download to fib -----------------------------------------------------------------------------Routing Tables: Public Destinations : 14 Routes : 14 Destination/Mask Destination/Ma sk
Proto
Pre
Cost
0.0.0.0/0 1.1.1.1/32 2.2.2.2/32 3.3.3.3/32 10.0.0.0/30 10.0.0.1/32 10.0.0.3/32 10.0.2.0/30 20.0.0.0/30 30.0.0.0/30 127.0.0.0/8 127.0.0.1/32 127.255.255.255/32 127.255.255.25 5/32 255.255.255.255/32 255.255.255.25 5/32
ISIS-L1 Direct ISIS-L1 ISIS-L1 Direct Direct Direct ISIS-L1 ISIS-L1 ISIS-L1 Direct Direct Direct Direct
15 0 15 15 0 0 0 15 15 15 0 0 0 0
10 0 10 20 0 0 0 20 20 30 0 0 0 0
Flags NextHop D D D D D D D D D D D D D D
10.0.0.2 127.0.0.1 10.0.0.2 10.0.0.2 10.0.0.1 127.0.0.1 127.0.0.1 10.0.0.2 10.0.0.2 10.0.0.2 127.0.0.1 127.0.0.1 127.0.0.1 127.0.0.1
Interface Ethernet0/0/8 LoopBack0 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 InLoopBack0 InLoopBack0 InLoopBack0 InLoopBack0
[2]dis ip routing-table [2]dis Route Flags: R - relay, D - download to fib -----------------------------------------------------------------------------Routing Tables: Public Destinations : 20 Routes : 20 Destination/Mask Destination/Ma sk
Proto
Pre
Cost
1.1.1.1/32 2.2.2.2/32 3.3.3.3/32 4.4.4.4/32 5.5.5.5/32 10.0.0.0/30 10.0.0.2/32 10.0.0.3/32 10.0.2.0/30 10.0.2.2/32 10.0.2.3/32 20.0.0.0/30 20.0.0.1/32 20.0.0.3/32 30.0.0.0/30 40.0.0.0/30 127.0.0.0/8 127.0.0.1/32 127.255.255.255/32 127.255.255.25 5/32 255.255.255.255/32 255.255.255.25 5/32
ISIS-L1 Direct ISIS-L1 ISIS-L2 ISIS-L2 Direct Direct Direct Direct Direct Direct Direct Direct Direct ISIS-L1 ISIS-L2 Direct Direct Direct Direct
15 0 15 15 15 0 0 0 0 0 0 0 0 0 15 15 0 0 0 0
10 0 10 10 20 0 0 0 0 0 0 0 0 0 20 20 0 0 0 0
Flags NextHop D D D D D D D D D D D D D D D D D D D D
10.0.0.1 127.0.0.1 10.0.2.1 20.0.0.2 20.0.0.2 10.0.0.2 127.0.0.1 127.0.0.1 10.0.2.2 127.0.0.1 127.0.0.1 20.0.0.1 127.0.0.1 127.0.0.1 10.0.2.1 20.0.0.2 127.0.0.1 127.0.0.1 127.0.0.1 127.0.0.1
Interface Ethernet2/0/0 LoopBack0 GigabitEthernet0/0/1 GigabitEthernet 0/0/1 GigabitEthernet0/0/0 GigabitEthernet 0/0/0 GigabitEthernet0/0/0 GigabitEthernet 0/0/0 Ethernet2/0/0 Ethernet2/0/0 Ethernet2/0/0 GigabitEthernet0/0/1 GigabitEthernet 0/0/1 GigabitEthernet0/0/1 GigabitEthernet 0/0/1 GigabitEthernet0/0/1 GigabitEthernet 0/0/1 GigabitEthernet0/0/0 GigabitEthernet 0/0/0 GigabitEthernet0/0/0 GigabitEthernet 0/0/0 GigabitEthernet0/0/0 GigabitEthernet 0/0/0 GigabitEthernet0/0/1 GigabitEthernet 0/0/1 GigabitEthernet0/0/0 GigabitEthernet 0/0/0 InLoopBack0 InLoopBack0 InLoopBack0 InLoopBack0
[5]display ip routing-table [5]display Route Flags: R - relay, D - download to fib -----------------------------------------------------------------------------Routing Tables: Public Destinations : 16 Routes : 16 Destination/Mask Destination/Ma sk 1.1.1.1/32 2.2.2.2/32 3.3.3.3/32 4.4.4.4/32 5.5.5.5/32 10.0.0.0/30 10.0.2.0/30
Proto
Pre
Cost
ISIS-L2 ISIS-L2 ISIS-L2 ISIS-L2 Direct ISIS-L2 ISIS-L2
15 15 15 15 0 15 15
30 20 20 10 0 30 30
Flags NextHop D D D D D D D
40.0.0.1 40.0.0.1 40.0.0.1 40.0.0.1 127.0.0.1 40.0.0.1 40.0.0.1
Interface Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 LoopBack0 Ethernet0/0/8 Ethernet0/0/8
20.0.0.0/30 30.0.0.0/30 40.0.0.0/30 40.0.0.2/32 40.0.0.3/32 127.0.0.0/8 127.0.0.1/32 127.255.255.255/32 127.255.255.25 5/32 255.255.255.255/32 255.255.255.25 5/32
ISIS-L2 ISIS-L2 Direct Direct Direct Direct Direct Direct Direct
15 15 0 0 0 0 0 0 0
20 20 0 0 0 0 0 0 0
D D D D D D D D D
40.0.0.1 40.0.0.1 40.0.0.2 127.0.0.1 127.0.0.1 127.0.0.1 127.0.0.1 127.0.0.1 127.0.0.1
Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 Ethernet0/0/8 InLoopBack0 InLoopBack0 InLoopBack0 InLoopBack0
ISIS cost for all interfaces is ') by default. It can be changed manually by 4isis cost’ command. Some other useful maintenance commands [1]dis [1] dis isis peer verbose Peer information for ISIS(1) System Id Interface Circuit Id State HoldTime Type PRI (priority for DIS election) ------------------------------------------------------------------------------0020.0200.2002 Eth0/0/8 0020.0200.2002.03 0020.0200.2002.0 3 Up 9s L1 64 MT IDs supported Local MT IDs Area Address(es) Peer IP Address(es) Uptime Adj Protocol Restart Capable Suppressed Adj Peer System Id
: : : : : : : : :
0(UP) 0 10 10.0.0.2 03:04:27 IPV4 YES NO 0020.0200.2002
Total Peer(s): 1 [1]display [1] display isis interface verbose Interface information for ISIS(1) --------------------------------Interface Id IPV4.State IPV6.State MTU Type DIS Eth0/0/8 001 Up Down 1497 L1/L2 No/No Circuit MT State : Standard Description : HUAWEI, AR Series, Ethernet0/0/8 Interface SNPA Address : 00e0-fc03-2b68 IP Address : 10.0.0.1 IPV6 Link Local Address : IPV6 Global Address(es) : Csnp Timer Value : L1 10 L2 10 Hello Timer Value : L1 10 L2 10 DIS Hello Timer Value : L1 3 L2 3 Hello Multiplier Value : L1 3 L2 3 LSP-Throttle Timer : L12 50 Cost : L1 10 L2 10 Ipv6 Cost : L1 10 L2 10 Priority : L1 64 L2 64 Retransmit Timer Value : L12 5 Bandwidth-Value : Low 100000000 High 0 Static Bfd : NO Dynamic Bfd : NO Fast-Sense Rpr : NO Interface Id IPV4.State IPV6.State MTU Type DIS Loop0 001 Up Down 1500 L1/L2 -Circuit MT State : Standard Circuit Parameters : passive Description : HUAWEI, AR Series, LoopBack0 Interface SNPA Address : 0000-0000-0000 IP Address : 1.1.1.1 IPV6 Link Local Address : IPV6 Global Address(es) : Csnp Timer Value : L12 10 Hello Timer Value : 10 DIS Hello Timer Value : Hello Multiplier Value : 3
Cost Ipv6 Cost Retransmit Timer Value LSP-Throttle Timer Bandwidth-Value Static Bfd Dynamic Bfd Fast-Sense Rpr
: : : : : : : :
L1 L1 L12 L12 Low NO NO NO
0 0 5 50
L2 L2
0 0
0
High
0
[1]dis [1] dis isis error Statistics of error packets for ISIS(1) --------------------------------------LSP packet errors: Longer LSP Mismatched Level Zero Sequence Number Zero Checksum Bad Authentication More Protocol TLV Bad Extended IS TLV Bad Reach TLV Mismatched Area Id(L1) Bad Alias TLV Bad SRLG TLV Bad Protocol ID Zero Lifetime Bad TE Router ID TLV
: : : : : : : : : : : : : :
0 0 0 0 0 0 0 0 0 0 0 0 0 0
Smaller LSP Invalid Sysid Illegal IS Type Incorrect Checksum Bad Auth Count Bad Nbr TLV Bad IF Addr TLV Bad Inter Domain TLV Bad TLV Length Bad Area TLV Unknown Adjacency Bad Version Bad Ext Reach TLV Bad TE Sub TLV
: : : : : : : : : : : : : :
0 0 0 0 0 0 0 0 0 0 0 0 0 0
Hello packet errors: Bad Packet Length : 0 Reserved CircType : 0 Repeated System ID : 0 Bad Circuit Type : 0 Longer packet : 0 More Area Addr : 0 Longer Area Addr : 0 Bad Area Addr TLV : 0 More IF Addr : 0 Bad Formatted IF TLV : 0 More Nbr SNPA(LAN) : 0 Invalid Sysid : 0 Bad TLV Length : 0 Zero HoldingTime : 0 Unusable IP Addr : 0 Repeated IPv4 Addr : 0 Mismatched Area Addr(L1): 0 Mismatched Proto : 0 SNPA Conflicted(LAN) : 0 Mismatched Level : 0 Mismatched Max Area Addr: 0 Bad Authentication : 0 More Auth TLV : 0 3-Way Option Error(P2P) : 0 No Area Addr TLV : 0 Bad Protocol ID : 0 Bad Version : 0 Invalid IPv6 Addr : 0 More IPv6 IF Addr : 0 Duplicate IPv6 Addr : 0 More Optional Checksum : 0 Bad Optional Checksum : 0 -------------------------------------------------------------------<1> debugging isis adjacency May 7 2013 16:17:06.629.1-0 16:17:06.629.1-05:13 5:13 1 ISIS/6/ISIS: ISIS-1-ADJ: Use level-1 IIH enconde cache to send IIH, Eth0/0/8.(IS15_2679) May 7 2013 16:17:06.629.2-0 16:17:06.629.2-05:13 5:13 1 ISIS/6/ISIS: ISIS-1-ADJ: Sending Lan L1 Hello on Eth0/0/8, to SNPA 0180.c200.0014.(IS15_6941) May 7 2013 16:17:07.319.1-0 16:17:07.319.1-05:13 5:13 1 ISIS/6/ISIS: ISIS-1-IIH: Set L1 holdtime on Eth0/0/8 for NBR 0020.0200.2002 as 9(IS21_968)
In this post I focused only on basic ISIS configuration. 1his protocol is widely used among ISPs. I will spend more time in the future to show you more functions and ISIS configuration e&les.
