L3 Routing Protocols – Things to know
ƒ
Each VDC supports 4 instances of each Interior Gateway Protocol (IGP)
(IE: EIGRP, ISIS, OSPF, RIPv2)
ƒ
Each VDC supports 1 instance of each Exterior Gateway Protocol (EGP)
(IE: MP-BGP)
ƒ
All routing protocols support Virtual Routing and Forwarding (VRF)
instances - VRF instances do not require unique protocol instances
ƒ
EIGRP, ISIS, OSPF, PBR and MP-BGP require the Enterprise Services
License
ƒ
The feature command is required to enable all routing protocols except
static routing
ƒ
The NX-OS supports 16 ECMP to a destination (user configurable)
ƒ
MP-BGP supports 2 and 4 Byte AS Numbers (plain-text & AS.dot notation)
ƒ
MP-BGP requires an address family configuration per neighbor
ƒ
OSPF always displays x.x.x.x notation regardless how it is entered
ƒ
OSPF is the only routing protocol that supports statefull synchronization
between supervisors (NSF is used for all other routing protocols)
1、EIGRP Configuration
EIGRP is a Cisco proprietary routing protocol. The EIGRP feature must
be enabled before an EIGRP instance or interface can be configured for
EIGRP. EIGRP is applied per interface instead of under the routing
process.
n7000(config)#
feature eigrp--Enable the EIGRP feature first!
n7000(config)#
router eigrp 10 --Create the instance
n7000(config-router)# router-id 192.168.1.1--specify a 32-bit router ID
n7000(config)# interface ethernet 2/1
n7000(config-if)#ip address 192.168.10.1 255.255.255.0
n7000(config-if)#ip router eigrp 10 --Enable the interface for EIGRP and
specify the EIGRP instance
Configuring a “Passive” Interface:
n7000(config)# interface ethernet 2/2
n7000(config-if)#
ip address 192.168.11.1/24
n7000(config-if)#
ip router eigrp 10
n7000(config-if)#
ip passive-interface eigrp 10
2、EIGRP Common Configuration Options
n7000(config-if)# ip ?
authentication Configures EIGRP authentication subcommands
bandwidth Set bandwidth for interface used in EIGRP metric calculation
bandwidth-percent Configures IP-EIGRP bandwidth limit
delay Set delay for interface used in EIGRP metric calculation
distribute-list Filter networks in routing updates
eigrp EIGRP interface configuration commands
hello-interval Configures IP-EIGRP hello interval
hold-time Configures IP-EIGRP hold time
load-sharing Style of load sharing
next-hop-self Configures IP-EIGRP next-hop-self
offset-list Add or subtract offset from EIGRP metrics
passive-interface Suppress routing updates on an interface
split-horizon Configures IP-EIGRP split-horizon on interface
summary-address Configures IP-EIGRP summary address on interface
n7000(config-router)# ?
address-family Configure an address-family
authentication Configures EIGRP authentication subcommands
autonomous-system Specify AS number for Address Family
default-information Control origination of a default route
default-metric Set metric of redistributed routes
distance Define an administrative distance
exit Exit from command interpreter
flush-routes Flush routes in RIB during restart
graceful-restart Peer resync without adjancency reset
log-adjacency-changes Log changes in adjacency state
log-neighbor-warnings Enable/Disable IP-EIGRP neighbor warnings
maximum-paths Forward packets over multiple paths
metric Modify EIGRP routing metrics and parameters
no Negate a command or set its defaults
redistribute Redistribute information from another routing protocol
router-id router-id for this EIGRP process
shutdown Shutdown this instance of EIGRP
stub Set IP-EIGRP as stubbed router
timers Set EIGRP timers
vrf Configure VRF information
EIGRP Process Verification
Use the show ip eigrp command to verify the EIGRP Instance configuration
n7000# show ip eigrp
IP-EIGRP AS 10 ID 192.168.1.1 VRF default
Process-tag: 10
Status: running
Authentication mode: none
Authentication key-chain: none
Metric weights: K1=1 K2=0 K3=1 K4=0 K5=0
IP proto: 88 Multicast group: 224.0.0.10
Int distance: 90 Ext distance: 170
Max paths: 8
Number of EIGRP interfaces: 3 (1 loopbacks)
Number of EIGRP peers: 2
3、
EIGRP Routing and Neighbor Verification
The following show commands are useful for viewing EIGRP routes and
verifying neighbor connectivity.
Verifying EIGRP Routes:
n7000# show ip eigrp route
IP-EIGRP Topology Table for AS(10)/ID(192.168.1.1) VRF default
P 192.168.1.1/32, 1 successors, FD is 128320
via Connected, loopback0
P 192.168.2.1/32, 2 successors, FD is 130816
via 192.168.10.2 (130816/128320), Ethernet2/1
via 192.168.11.2 (130816/128320), Ethernet2/2
Verifying Neighbors:
n7000# show ip eigrp neighbors
IP-EIGRP neighbors for process 10 VRF default
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
1 192.168.11.2 Eth2/2 14 00:07:52 8 300 0 24
0 192.168.10.2 Eth2/1 13 00:07:52 6 300 0 23
n7000# show ip eigrp neighbor detail
IP-EIGRP neighbors for process 10 VRF default
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
1 192.168.11.2 Eth2/2 13 00:10:20 8 300 0 24
Version 12.4/1.2, Retrans: 1, Retries: 0, Prefixes: 2
0 192.168.10.2 Eth2/1 12 00:10:21 6 300 0 23
Version 12.4/1.2, Retrans: 1, Retries: 0, Prefixes: 2
4、OSPFv2 Configuration
OSPFv2 is a standard based routing protocol defined in RFC 2328. The
OSPF feature must be enabled before an OSPF instance can be
configured. OSPF is applied per interface instead of under the routing
process.
n7000(config)#
feature ospf
n7000(config)#
router ospf 10
n7000(config-router)# router-id 192.168.1.1
n7000(config)# interface ethernet 1/13
n7000(config-if)# ip address 192.168.10.1 255.255.255.0
n7000(config-if)# ip router ospf 10 area 0
Configuring a “Passive” Interface:
n7000(config)# interface eth 1/1
n7000(config-if)# ip address 192.168.10.1 255.255.255.0
n7000(config-if)#
ip router ospf 10 area 0
n7000(config-if)#
ip ospf passive-interface
OSPFv2 Common Configuration Options
n7000(config-if)# ip ospf ?
authentication Authentication on the interface
authentication-key Configure the authentication key for the interface
cost Cost associated with interface
dead-interval Dead interval
hello-interval Hello interval
message-digest-key Message digest authentication password (key)
mtu-ignore Disable OSPF MTU mismatch detection
network Network type
passive-interface Suppress routing updates on the interface
priority Router priority
retransmit-interval Packet retransmission interval
shutdown shutdown ospf on this interface
transmit-delay Packet transmission delay
n7000(config-router)# ?
area Configure area properties
auto-cost Calculate OSPF cost according to bandwidth
default-information Control distribution of default route
default-metric Specify default metric for redistributed routes
distance OSPF administrative distance
exit Exit from command interpreter
flush-routes Flush routes on a non-graceful controlled restart
graceful-restart Configure graceful restart
log-adjacency-changes Log changes in adjacency state
max-metric Maximize the cost metric
maximum-paths Maximum paths per destination
no Negate a command or set its defaults
policy Policy related information
protocol OSPF protocol
redistribute Redistribute information from another routing protocol
router-id Set OSPF process router-id
summary-address Configure route summarization for redistribution
timers Configure timer related constants
vrf Display per-VRF information
OSPFv2 Process Verification
Use the show ip ospf command to verify the OSPF configuration.
n7000# show ip ospf
Routing Process 10 with ID 192.168.1.1 VRF default
Stateful High Availability enabled
Graceful-restart is configured
grace period: 60, state: (null)
Last graceful restart exit status: None
Supports only single TOS(TOS0) routes
Supports opaque LSA
Administrative distance 110
Reference Bandwidth is 40000 Mbps
Initial SPF schedule delay 200.000 msecs,
minimum inter SPF delay of 1000.000 msecs,
maximum inter SPF delay of 5000.000 msecs
Minimum hold time for Router LSA throttle 5000.000 ms
Minimum hold time for Network LSA throttle 5000.000 ms
Minimum LSA arrival 1000.000 msec
Maximum paths to destination 8
Number of external LSAs 0, checksum sum 0
Number of opaque AS LSAs 0, checksum sum 0
Number of areas is 1, 1 normal, 0 stub, 0 nssa
Number of active areas is 1, 1 normal, 0 stub, 0 nssa
Area BACKBONE(0)
Area has existed for 00:05:55
Interfaces in this area: 2 Active interfaces: 2
No authentication available
SPF calculation has run 6 times
Last SPF ran for 0.000588s
Area ranges are
Number of LSAs: 3, checksum sum 0x16114
<Text Omitted>
OSPFv2 Routing and Neighbor Verification
The following show commands are useful for viewing OSPF routes and
verifying neighbor connectivity.
Verifying OSPFv2 Routes:
n7000# show ip ospf route
OSPF Process ID 10 VRF default, Routing Table
(D) denotes route is directly attached (R) denotes route is
in RIB
192.168.1.1/32 (intra)(D) area 0
via 192.168.1.1/Lo0*, cost 1
192.168.10.0/24 (intra)(D) area 0
via 192.168.10.1/Eth1/13*, cost 40
Verifying Neighbors:
n7000# show ip ospf neighbor
OSPF Process ID 10 VRF default
Total number of neighbors: 1
Neighbor ID Pri State Up Time Address Interface
192.168.2.1 1 FULL/DR 00:00:27 192.168.10.2 Eth1/13
n7000# show ip ospf neighbor detail
Neighbor 192.168.2.1, interface address 192.168.10.2
Process ID 10 VRF default, in area 0 via interface Ethernet1/13
State is FULL, 6 state changes, last change 00:00:57
Neighbor priority is 1
DR is 192.168.10.2 BDR is 192.168.10.1
Hello options 0x2, dbd options 0x42
Last non-hello packet received 00:00:49
Dead timer due in 00:00:37
OSPFv2 Troubleshooting Commands
n7000# restart ospf 10
n7000# clear ip ospf 10 neighbor ?
* Clear all neighbors
A.B.C.D Source IP address, or router ID of the neighbor
ethernet Ethernet IEEE 802.3z
loopback Loopback interface
port-channel Port Channel interface
n7000# debug ip ospf ?
10 Process tag
adjacency Adjacency events
all All OSPF debugging
database OSPF LSDB changes
database-timers OSPF LSDB timers
events OSPF related events
flooding LSA flooding
graceful-restart OSPF graceful restart related debugs
ha OSPF HA related events
hello Hello packets and DR elections
lsa-generation Local OSPF LSA generation
packets OSPF packets
policy OSPF RPM policy debug information
redist OSPF redistribution
retransmission OSPF retransmission events
spf SPF calculations
spf-trigger Show SPF triggers