Load balancing and Variance
LAB24: EIGRP – IPv6
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LAB 24: Diagram
Note: This Lab was developed on Cisco IOS Version15.2(4) M1 ADVENTERPRISEK9-M.
LAB24: IPv6 EIGRP Load balancing and Variance
Task 1: Configure IPv6 EIGRP Load balancing and variance
Configure redundant path between two routers
R1:
interface serial 2/0
ipv6 address 12::1/64 eui-64
no shutdown
interface serial 2/3
ipv6 address 21::1/64 eui-64
no shutdown
interface loopback 1
ipv6 address 11:0:1::1/64
interface loopback 2
ipv6 address 11:0:2::1/64
interface loopback 3
ipv6 address 11:0:3::1/64
exit
R2:
interface serial 2/0
ipv6 address 12::2/64 eui-64
no shutdown
interface serial 2/3
ipv6 address 43::2/64 eui-64
no shutdown
interface ethernet 0/0
ipv6 address 23::2/64 eui-64
no shutdown
interface loopback 1
ipv6 address 22:0:1::2/64
interface loopback 2
ipv6 address 22:0:2::2/64
interface loopback 3
ipv6 address 22:0:3::2/64
exit
R3:
interface serial 2/0
ipv6 address 34::3/64 eui-64
no shutdown
interface serial 2/3
ipv6 address 21::3/64 eui-64
no shutdown
interface ethernet 0/0
ipv6 address 23::3/64 eui-64
no shutdown
interface loopback 1
ipv6 address 33:0:1::3/64
interface loopback 2
ipv6 address 33:0:2::3/64
interface loopback 3
ipv6 address 33:0:3::3/64
exit
R4:
interface serial 2/0
ipv6 address 34::1/64 eui-64
no shutdown
interface serial 2/3
ipv6 address 43::4/64 eui-64
no shutdown
interface loopback 1
ipv6 address 44:0:1::4/64
interface loopback 2
ipv6 address 44:0:2::4/64
interface loopback 3
ipv6 address 44:0:3::4/64
exit
Configure IPv6 EIGRP to learn routes over multiple paths
R1:
ipv6 unicast-routing
ipv6 router eigrp 100
interface serial 2/0
ipv6 eigrp 100
interface serial 2/3
ipv6 eigrp 100
interface loopback 1
ipv6 eigrp 100
interface loopback 2
ipv6 eigrp 100
interface loopback 3
ipv6 eigrp 100
exit
R2:
ipv6 unicast-routing
ipv6 router eigrp 100
interface serial 2/0
ipv6 eigrp 100
interface serial 2/3
ipv6 eigrp 100
interface ethernet 0/0
ipv6 eigrp 100
interface loopback 1
ipv6 eigrp 100
interface loopback 2
ipv6 eigrp 100
interface loopback 3
ipv6 eigrp 100
exit
R3:
ipv6 unicast-routing
ipv6 router eigrp 100
interface serial 2/0
ipv6 eigrp 100
interface serial 2/3
ipv6 eigrp 100
interface ethernet 0/0
ipv6 eigrp 100
interface loopback 1
ipv6 eigrp 100
interface loopback 2
ipv6 eigrp 100
interface loopback 3
ipv6 eigrp 100
exit
R4:
ipv6 unicast-routing
ipv6 router eigrp 100
interface serial 2/0
ipv6 eigrp 100
interface serial 2/3
ipv6 eigrp 100
interface loopback 1
ipv6 eigrp 100
interface loopback 2
ipv6 eigrp 100
interface loopback 3
ipv6 eigrp 100
exit
Step 3 Dual Diffusion algorithm’s rule:
For a path to be even considering as a valid path its Advertise Distance (AD) should be less than 2 times current Feasible Distance (FD).
Valid path = AD < 2*current FD
Example:
(NOTE: On R3 Router there are 3 paths to reach 22:0:2::2/64 network:
1) Via 23::2/64 eui-64 2) Via 21::1/64 eui-64 3) via 34::/64 eui-64 but as seen below in the Topology Table of R3 there is only one path seen to reach 22:0:2::2/64 network.)
R3#show ipv6 eigrp topology
P 22:0:2::/64, 1 successors, FD is 409600
via FE80::A8BB:CCFF:FE00:200 (409600/128256), Ethernet0/0
(This is because of the rule that says “For a path to become a valid path its Advertised Distance (AD) should be less than 2 times current Feasible Distance (FD).
Valid path = AD < 2*current FD
As seen below in the Topology Table of R1 Router, its FD to reach 22:0:2::/64 is 2297856.
This is the FD that R1 is advertising to R3 router, which becomes AD to Reach 22:0:2::/64.
Now because this AD (2297856) is not less than 2 times current FD ( 2 X 409600 = 819200) hence it is not reflecting in the topology table.
Similarly path via 34:0::0:4/64 is also not reflecting.
R1#show ip eigrp topology
P 33:0:2::/64, 1 successors, FD is 2297856
via FE80::A8BB:CCFF:FE00:300 (2297856/128256), Serial2/3
via FE80::A8BB:CCFF:FE00:200 (2323456/409600), Serial2/0
For a path to become Feasible Successor (FS) its Advertise Distance (AD) should be less than current Feasible Distance (FD)
FS = AD < current FD
Example:
(NOTE: On R1 Router there are 2 paths to reach 33:0:2::/64 network:
1) Via 12::2/64 eui-64 2) Via 21::3/64 eui-64.
As seen below in the Topology Table of R1 Router, path via 21::2/64 eui-64 is successor, as its FD (2297856) is lower compared to the FD provided by path via 12::2/64 eui-64.
Now the 2nd path via 12::2/64 eui-64 will considered as Feasible successor if it meets the following criteria
FS = AD < current FD
For a path to become Feasible Successor (FS) its Advertise Distance (AD) should be less than current Feasible Distance (FD)
Path Via 12::2/64 eui-64 has AD 409600 that is less than current FD 2297856 hence is will be considered as FS. )
R1#show ipv6 eigrp topology
P 33:0:2::/64, 1 successors, FD is 2297856
via FE80::A8BB:CCFF:FE00:300 (2297856/128256), Serial2/3
via FE80::A8BB:CCFF:FE00:200 (2323456/409600), Serial2/0
Step 4 Verify that only best routes are reflecting in routing table.
R1#show ipv6 route
IPv6 Routing Table - default - 23 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea
IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect
O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
C 11:0:1::/64 [0/0]
via Loopback1, directly connected
L 11:0:1::1/128 [0/0]
via Loopback1, receive
C 11:0:2::/64 [0/0]
via Loopback2, directly connected
L 11:0:2::1/128 [0/0]
via Loopback2, receive
C 11:0:3::/64 [0/0]
via Loopback3, directly connected
L 11:0:3::1/128 [0/0]
via Loopback3, receive
C 12::/64 [0/0]
via Serial2/0, directly connected
L 12::A8BB:CCFF:FE00:100/128 [0/0]
via Serial2/0, receive
C 21::/64 [0/0]
via Serial2/3, directly connected
L 21::A8BB:CCFF:FE00:100/128 [0/0]
via Serial2/3, receive
D 22:0:1::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 22:0:2::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 22:0:3::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 23::/64 [90/2195456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 33:0:1::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 33:0:2::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 33:0:3::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 34::/64 [90/2681856]
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 43::/64 [90/2681856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 44:0:1::/64 [90/2809856]
via FE80::A8BB:CCFF:FE00:300, Serial2/3
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 44:0:2::/64 [90/2809856]
via FE80::A8BB:CCFF:FE00:300, Serial2/3
via FE80::A8BB:CCFF:FE00:200, Serial2/0
D 44:0:3::/64 [90/2809856]
via FE80::A8BB:CCFF:FE00:300, Serial2/3
via FE80::A8BB:CCFF:FE00:200, Serial2/0
L FF00::/8 [0/0]
via Null0, receive
Step 5 Configure Variance command in IPv6 EIGRP Process
R1:
ipv6 router eigrp 100
variance 2
exit
(EIGRP supports Unequal Metric Path Load Balancing with the help of Variance.)
Step 6 Verify that multiple paths are reflecting in routers IPv6 routing table
R1#show ipv6 route
IPv6 Routing Table - default - 23 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea
IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect
O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
C 11:0:1::/64 [0/0]
via Loopback1, directly connected
L 11:0:1::1/128 [0/0]
via Loopback1, receive
C 11:0:2::/64 [0/0]
via Loopback2, directly connected
L 11:0:2::1/128 [0/0]
via Loopback2, receive
C 11:0:3::/64 [0/0]
via Loopback3, directly connected
L 11:0:3::1/128 [0/0]
via Loopback3, receive
C 12::/64 [0/0]
via Serial2/0, directly connected
L 12::A8BB:CCFF:FE00:100/128 [0/0]
via Serial2/0, receive
C 21::/64 [0/0]
via Serial2/3, directly connected
L 21::A8BB:CCFF:FE00:100/128 [0/0]
via Serial2/3, receive
D 22:0:1::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 22:0:2::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 22:0:3::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 23::/64 [90/2195456]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 33:0:1::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 33:0:2::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 33:0:3::/64 [90/2297856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 34::/64 [90/2681856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 43::/64 [90/2681856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 44:0:1::/64 [90/2809856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 44:0:2::/64 [90/2809856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
D 44:0:3::/64 [90/2809856]
via FE80::A8BB:CCFF:FE00:200, Serial2/0
via FE80::A8BB:CCFF:FE00:300, Serial2/3
L FF00::/8 [0/0]
via Null0, receive
(Variance commands will set the benchmark and IPv6 EIGRP Router will Load Balancing the traffic between the paths within that benchmark which is reflected in router’s IPv6 routing table.)
