EIGRP notes
conf t
router eig 100
no auto
net 131.1.1.0 0.0.0.255
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configure the hello and dean interval to 20 and 80
int s1/0.12
ip hello-intercal eigrp 300 20
ip hold-time eigrp 300 80
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change the k values
router eigrp 100
metric weight 0 1 0 0 0 0
———————————————-
as200 using only the delay parameter to calulate their composite metric
router eigrp 100
metric weight 0 0 0 1 0 0
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1 – advertise a summary route
int s1/0.12ip summary-address eigrp 300 1.1.0.0 255.255.252.0
2 – only one summary cmd per neightbor
int s1/0.13
no ip add
int virtual-template 13
ip address 131.1.13.1 255.255.255.0
ip summary-address eigrp 300 1.1.0.0 255.255.252.0 leak-map R1-R3
route-map R1-R3 perm 10
match ip add 1
access-list 1 per 1.1.1.0 0.0.0.255
———whatever is permitted in the acl will be leaked along the summary route.
eg..
D 1.1.0.0/22 [90/2297856] via 131.1.100.1, 00:00:06, Serial1/2
D 1.1.1.0/24 [90/2297856] via 131.1.100.1, 00:00:49, Serial1/2
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R1 should avcertise the summary route plus all the specific networks to R4
int s1/0.14
no ip address
int virtual-template 14
ip summary-address eigr p300 1.1.0.0 255.255.252.0 leak-map R1-4
int s1/0.14
frame-relay dlci 104 ppp virtual-template 14
—–note: if a leak-map references a route-map with no acl or and acl that does not exist, the summary plus all specific routes are advertised.
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unequal cost load balancing.
— in order to perform unequal cost load balancing, the advertised distance of the worst route should be lower then the feasible distance.
eg.
R4(config-fr-dlci)#do sho ip eigrp 400 topo 131.1.56.0/24
IP-EIGRP (AS 400): Topology entry for 131.1.56.0/24
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 2195456 <<<<<<<<<<<<<<<<<<<<<<< FD
Routing Descriptor Blocks:
131.1.46.6 (Serial1/0.46), from 131.1.46.6, Send flag is 0×0
Composite metric is (2195456/281600), Route is Internal
Vector metric:
Minimum bandwidth is 1544 Kbit
Total delay is 21000 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 1
131.1.45.5 (Serial1/0.45), from 131.1.45.5, Send flag is 0×0
Composite metric is (5537536/281600), Route is Internal <<<<<<<<
Vector metric:
Minimum bandwidth is 512 Kbit
Total delay is 21000 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 1
———–now divide the worst route by the best route.
5537536(worst) / 2195456(best) = 2.522 – round up to 3
router eigrp 400
variance 3
sho ip route ei 400
131.1.0.0/16 is variably subnetted, 14 subnets, 2 masks
D 131.1.56.0/24 [90/2195456] via 131.1.46.6, 00:00:31, Serial1/0.46
[90/5537536] via 131.1.45.5, 00:00:31, Serial1/0.45
———————————————————————-
disable the stuck in active timer for as 300 and set the SIA timer for 60 min for AS 100.
router eigrp 300
timers active-time disabled.
router eigrp 100
timers actiive-time 60
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configure authentication
r1
key chain R1-2
key 1
key-string cisco12
int s1/0.12
ip authenti key-chain eigrp 300 R1-2
ip authenti mode eigrp 300 md5
sh ip eigrp int detail <– to see the authentication
sh ip route eigrp 300
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bb2 should avdertise eigrp routes with greater then 110 hops as unreachable
router eigrp 200
metric maximum-hops 110
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change the admin distance; internal 95 / external 138
router eigrp 100
distance eigrp 95 138
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use 30% of e0/0’s link for exchanging updates.
int e0/0
ip bandwidth-percent eigrp 200 30
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bb1 should use 15 mbps of it’s links bandwidth do not use ip bandwidth-percent command.
int e0/0
bnadwidth 30000
———–by default eigrp uses 50% of the bnadwidth
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bb1 should receive routes from R1 but not advertise routes to R1. Do not use any global config cmd.
router eigrp 100
eigrp stub receive-only
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config loop1 151.1.112.112/24 in bb2 and advertise this route in as 200. the route should appear as an external route.
int loop1
ip address 151.1.112.112 255.255.255..0
access-list 1 permit 151.1.112.0 0.0.0.255
route-map EX_ROUTE perm 10
mathc ip add 1
router eig 200
redistribue connected route-map EX_ROUTE
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config a statis route on bb2 for 161.1.112.0/24 to null0. redistribute into eigrp with a metric of bandwidth 1500, load-1, delay -20000, reliability – 255, mtu 1500
ip route 161.1.112.0 255.255.255.0 null0
router ei 100
default-metric 1500 20000 255 1 1500
redistibute static
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config bb2 so that it only advertises static routes that are redistributed and connected networks that are advertised in EIGRP. do not use a global cmd.
router eigrp 200
eigrp stub connected static
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config r5 not to log changes in eigrp nei adj
router ei 400
no eigrp log-neighbor-changes
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config r6 to log nei warning messages for eigrp 400 and repeat the warning every 5 min.
router eigrp 400
eigrp log-neighbor-warning 300
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config r3 to add a delay of 50 to allthe routes learned from R1 through it’s FR connecton
router eigrp 300
offset-list 0 in 50 virtual-template 31
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config r4 to redistibute between as30 and as 400
router eigrp 300
redistribute eigrp 400
router eigrp 400
redistribute ei 300
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config r 2 ri inject a default route into as200 – do not use any global config cmd.
int e0/0
ip summary-address eigrp 200 0.0.0.0 0.0.0.0
the other way is through a global cmd – redistribute static
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config r1 to redisribute between as 100 and as 300, in the future there wil be anoher redistribution point, the router must prevent feed back when the second redistribution point is added.
route-map 100-300 deny 10
match tag 300
route-map 100-300 permit 20
set tag 100
route-map 300-100 deny 10
match tag 100
route-map 300-100 per 20
set tag 300
router eigrp 100
redistribute eigrp 300 route-map 300-100
router eigrp 300
redistribute eigrp 1oo route-map 100-300
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configure mutual redistribution between ospf and eigrp
router ospf 1
redistribute eigrp 100 subnets
router eigrp 100
redistribute ospf 1 metric 1 1 1 1 1 <— must specify a metric
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advertise only directly conencted interfaces that are advertised with a network command.
router ei 100
eigrp stub connected
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config r1 so that r2 and r3 have netw 2.2.2.2/24 and 3.3.3.3/24 in thier routing table. do not use remove ei stub connect.
access-list 1 per 2.2.2.0 0.0.0.255
access-list 1 per 3.3.3.0 0.0.0.255
route-map LEAK per 10
match ip add 1
eigrp 100
eigrp stub connected leak-map
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reconfig r1 so r2 only gets 2.2.2.0/24 and r3 only gets 3.3.3.0/24- do not remove eigrp stub connected
access-list 2 per 2.2.2.0 0.0.0.255
access-list 3 per 3.3.3.0 0.0.0.255
route-map LEAK per 10
match ip add 2
match inter s0/0.12
route-map LEAK per 20
match ip add 3
match int s1/0.13
——————————————————————–
advertise directly connected interfaces
rouer ei 100
no auo
net 2.0.0.0
net 10.1.12.1 0.0.0.0
————————————————
config r1 2.0.0.0/8 as a candidate default route for r2/r3
ip default-network 2.0.0.0
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config r2 so that r3 does not user net 2.0.0.0/8 as the candidate default
router ei 10
no default-informaton allowed out < – this disables redistribution of a default route
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new cmd
sho ip eigrp event
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whats the difference between network 2.0.0.0 and network 2.0.0.0 0.0.0.0?
net 2.0.0.0 0.0.0.0 will not work.
int loop 2
ip add 2.2.2.2 255.0.0.0
router ei 100
net 2.0.0.0 or net 2.2.2.2 will be net 2.0.0.0 or you can enter net 2.0.0.0 0.255.255.255 eigrp will convert to net 2.0.0.0
—> network 2.0.0.0 0.0.0.0 <— 0.0.0.0 will match only 2.0.0.0
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advertise a candidate default router
ip default-network 1.0.0.0
sh ip route eigrp
D* 1.0.0.0/8……..
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config r2 to use 2.0.0.0/8 & r3 to use 3.0.0.0/8 as the candidate default.
r2
access-list 2 permit 2.0.0.0
router eigr 100
default-information allowed in 2
r3
access-list 3 permit 3.0.0.0
router ei 100
default-information allowed in 3
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configure r2 so that r3 does not use net 2.0.0.0/8 as the candidate default
router ei 100
no default-information allowed out < — this disables the redistribution of default route, r3 will no longer use network 2.0.0.0/8 as its candidate default, but it will still have that network in it’s routing table.
do clear ip eigrp nei
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remove no default-information allowed out from r2 and config r3 to deny the candidate default 2.0.0.0/8
router eigrp 100
default-information allowed in
do clear ip eigrp nei
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2 ways to injet a default route
ip summary-dadress eigrp 0.0.0. 00.0.0.0
ip route x.x.x.x 0.0.0.0 0.0.0.0
router ei 100
redistribute static
———————————————————-
no ip split-horizon – enable on multipoint interfaces – always enable on NBMA-multipoint interfaces.
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advertise 10.1.1.1/32
router eigrp 1
net 10.1.1.1 0.0.0.0
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advertise connected and summary routes
router ei 1
eigrp stub
———————————————–
advertise connected and static routes
router ei 1
eigrp stub connected static
—————————————–
connected, summary, and static routes will not be sent
eigrp stub receive-only
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eigrp mutual redistribution, tag routes example
router eigrp 100
net 10.1.1.0 0.0.0.255
redistribut eigrp 200 route-map 200to100
route-map 200to100 deny 10
match tag 100
route-map 200to100 permit 20
set tag 200
router eigrp 200
net 10.1.2.0 0.0.0.255
redistribute ei 100 route-map 100to200
route-map 100to200 deny 10
match tag 200
route-map 100to200 permit 20
set tag 100
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eigrp should use bandwidth, load, and delay in route calculation
metric weights 0 1 1 1 0 0
—k1 = bandwidth, k2 = load, k3 = delay, k4 = reliability & k5 = MTU.
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summary route creates a route to null0
Note You should not use the ip summary-address eigrp summarization command to generate the default route (0.0.0.0) from an interface. This causes the creation of an EIGRP summary default route to the null 0 interface with an administrative distance of 5. The low administrative distance of this default route can cause this route to displace default routes learned from other neighbors from the routing table. If the default route learned from the neighbors is displaced by the summary default route, or if the summary route is the only default route present, all traffic destined for the default route will not leave the router, instead, this traffic will be sent to the null 0 interface where it is dropped.
The recommended way to send only the default route out a given interface is to use a distribute-list command. You can configure this command to filter all outbound route advertisements sent out the interface with the exception of the default (0.0.0.0).
you can get rid of it by using the admin distance
int s1/0
ip summary-address ei 10 0.0.0.0 0.0.0.0 250
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calcualting the composite metric along the path for 150.1.111.0/24
Ethernet0/0 is up, line protocol is up
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
10,000,000 / slowest BW 10000 = 1000
sum of all interface delays 1000 = 1000 / 10 = 100
(1000+100)*256=281600 but since we told eigrp to only use bandwidth via metric weights 0 1 0 0 0 0 command in a previous task we see:
(1000)*256+256000 in the routing table
D 150.1.111.0 [90/256000] via 131.1.111.111, 00:01:22, Ethernet0/0
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show ip eigrp neighbor detail
debug eigrp packet stub
————————————-
You can enter a subnet mask or a wildcard mask
router ei 3
net 10.1.1.0 0.0.0.255 or net 10.1.1.0 255.255.255.0
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ip summary-address eigrp
To configure a summary aggregate address for a specified interface, use the ip summary-address eigrp command in interface configuration mode. To disable a configuration, use the no form of this command.
ip summary-address eigrp as-number ip-address mask [admin-distance] [leak-map name]
no ip summary-address eigrp as-number ip-address mask
Syntax Description
|
|
|
as-number
|
Autonomous system number.
|
|
ip-address
|
Summary IP address to apply to an interface.
|
|
mask
|
Subnet mask.
|
|
admin-distance
|
(Optional) Administrative distance. A value from 0 to 255.
|
|
leak-map name
|
(Optional) Route-map reference to configure route leaking through the summary.
|
Defaults
•
An administrative distance of 5 is applied to Enhanced Interior Gateway Routing Protocol (EIGRP) summary routes.
•EIGRP automatically summarizes to the network level, even for a single host route.
•No summary addresses are predefined.
•The default administrative distance metric for EIGRP is 90.
Usage Guidelines
The ip summary-address eigrp command is used to configure interface-level address summarization. EIGRP summary routes are given an administrative distance value of 5. The administrative distance metric is used to advertise a summary without installing it in the routing table.
By default, EIGRP summarizes subnet routes to the network level. The no auto-summary command can be entered to configure subnet level summarization.
EIGRP Support for Leaking Routes
Configuring the leak-map keyword allows to advertise a component route that would otherwise be suppressed by the manual summary. Any component subset of the summary can be leaked. A route map and access list must be defined to source the leaked route.
The following is default behavior if an incomplete configuration is entered:
•If the leak-map keyword is configured to reference a nonexistent route map, the configuration of this keyword has no effect. The summary address is advertised but all component routes are suppressed.
•If the leak-map keyword is configured but the access-list does not exist or the route map does not reference the access list, the summary address and all component routes are sent.
Examples
The following example configures an administrative distance of 95 on interface Ethernet 0/0 for the 192.168.0.0/16 summary address:
Router(config)# router eigrp 1
Router(config-router)# no auto-summary
Router(config-router)# exit
Router(config)# interface Ethernet 0/0
Router(config-if)# ip summary-address eigrp 1 192.168.0.0 255.255.0.0 95
The following example configures the 10.1.1.0/24 subnet to be leaked through the 10.0.0.0 summary address:
Router(config)# router eigrp 1
Router(config-router)# exit
Router(config)# access-list 1 permit 10.1.1.0 0.0.0.255
Router(config)# route-map LEAK-10-1-1 permit 10
Router(config-route-map)# match ip address 1
Router(config-route-map)# exit
Router(config)# interface Serial 0/0
Router(config-if)# ip summary-address eigrp 1 10.0.0.0 255.0.0.0 leak-map LEAK-10-1-1
Router(config-if)# end
---------------------------------------------------
variance (EIGRP)
To control load balancing in an internetwork based on the Enhanced Interior Gateway Routing Protocol (EIGRP), use the variance command in router configuration mode. To reset the variance to the default value, use the no form of this command.
variance multiplier
no variance
Syntax Description
|
|
|
multiplier
|
Metric value used for load balancing. It can be a value from 1 to 128. The default is 1, which means equal-cost load balancing.
|
Defaults
1 (equal-cost load balancing)
Command Modes
Router configuration
Usage Guidelines
Setting a variance value enables EIGRP to install multiple loop-free routes with unequal cost in a local routing table. A route learned through EIGRP must meet two criteria to be installed in the local routing table:
•The route must be loop- free. This condition is satisfied when the reported distance is less than the total distance or when the route is a feasible successor.
•The metric of the route must be lower than the metric of the best route (the successor) multiplied by the variance configured on the router.
Thus, if the variance is set to 1, only routes with the same metric as the successor are installed in the local routing table. If the variance is set to 2, any EIGRP-learned route with a metric less than 2 times the successor metric will be installed in the local routing table.
Note EIGRP does not load-share between multiple routes; it only installs the routes in the local routing table. Then, the local routing table enables switching hardware or software to load-share between the multiple paths.
Examples
The following example sets a variance value of 4:
router eigrp 109
variance 4
The following example sets a variance value of 2:
ipv6 router eigrp 11
variance 2
timers active-time
To adjust routing wait time, use the timers active-time command in router configuration mode. To disable this function, use the no form of the command.
timers active-time [time-limit | disabled]
no timers active-time
Syntax Description
|
| time-limit |
(Optional) Enhanced Interior Gateway Routing Protocol (EIGRP) active-time limit (in minutes). The time range is from 1 to 4294967295. |
| disabled |
(Optional) Disables the timers and permits the routing wait time to remain active indefinitely. |
Defaults
This command is disabled by default.
Usage Guidelines
In EIGRP, there are timers
that control the time the router waits (after sending a query) before
declaring the route to be in the stuck in active (SIA) state.
Examples
In the following example, the routing wait time is 200 minutes on the specified route:
router eigrp 5
timers active-time 200
In the following example, the routing wait time is indefinite on the specified route:
router eigrp 5
timers active-time disabled
In the following example, the routing wait time is 100 minutes on the specified route:
ipv6 router eigrp 1
timers active-time 100
-----------------------------------------------------
When you adjust the ip hello-intervalyou also need to adjust the ip hold-time eigrp.
-----------------------------------------------------------------------------------------
- EIGRP does not build peer relationships over secondary addresses
- EIGRP and Frame-relay you need to use broadcast keyword in the frame map statements, (without broadcast keyword the adjacencies will not form)
- Don’t forget to disable split horizon on the hub no ip split-horizon eigrp – fyi ip split-horizon has nothing to do with no ip split-horizon eigrp
- adjust delay to manipulate the path
- eigrp uses the minimum bandwidth on the path to a destination network and the total delay to compute routing metrics. (config on int)
- bandwidth = 1,000,000/bandwidth(i))*256 – where (i) is the lowest bandwidthof al loutgoping interfaces on the orut to the destination represented in kilobits.
- delay = delay(i) *256 – where (i) is the sum of the delays configured on the interfaces on the route to the destination network in tens of microseconds, so you must divide by 10 before you use it in this formula.
- to determine total metric – metric=[k1*bandwidth+(k2*bandwidth)/(256-load_+k3*delay]*[k5/(reliability +k4)]
- mismatched K vlaues will prevent a neightbot relatioinship from being built.
- default k values k1 =1 k2=0 k3=1 k4=0 k5=0
- to simplify metric = bandwidth + delay
feasible distance = the best metric along the path to a destination network, including the metric to the neighbor advertising that path.
reported distance = is the total metric along the path to a destinatipon network as advertised byu the upstream neighbor.
feasible successor = is a path whose reported distance is less than the feasible distance (the current best path)
You can see the routes that are not feasible successors using sh ip eigrp topology all-links
SIA happens when a query takes to long to be answered. Usually querys are not answered due to high cpu, memory problems, circuit issue, and unidirectional links.
Troubleshooting SIA
- find the routes that are consistently being reproted as SIA – sho ip eigrp topo active
- find the router thsi is consistently failing to answer the queries for these routes
- find the reason that router is ntot receiving or answering queries
If you see and R then the neighbors have not replied yet. Pay attention to Active for 2-3 min & outstanding replies.
—————————————————————————————————————
redistribution between 2 eigrp AS’s
router ei 200
redistribute eigrp 100 route-map to-eigrp200
network 10.1.1.0 0.0.0.255
router ei 100
redistribute eigrp 200 route-map to-eigrp100
net 172.16.1.0 0.0.0.255
route-map to-eigrp100 deny 10
match tag 100
route-map to-eigrp100 permit 20
set tag 200
route-map to-eigrp200 deny 10
match tag 200
route-map to-eigrp200 permit 20
set tag 100
NOTE: routes from eigrp 100 are tagged 100 before redistributing them to eigrp 200. When the routes from eigrp 200 are redistributed back to eigrp 100, the routes with 100 tags are denied to ensure a loop-free topology.
————————————————————————————————————————-
always use a default metric when redistributing eigrp into other routing protocols. routes redistributed into eigrp are not always summarized. external eigrp routes have an admin distance of 170.
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if you create a static route (ip route 10.1.1.0 255.255.255.0 serial 1) and also use a network statement under router eigrp (network 10.0.0.0) then the router will redistribute the route even though it is not redistributing static routes!
————————————————————————————————————–
if you use auto summary you will see routes to Null0 to see all the routes use no auto.
—————————————————————————————————-
inter s1
ip bandwidth-percent eigrp 2 <1-999999 max bandwidth % to use>
———————————————————–
2 ways to inject a default route into eigrp
redistribute static – use this method when you want to advertise connections to the internet.
ip route 0.0.0.0 0.0.0.0 x.x.x.x (next hop to the internet)
router ei 1
redistribute static
default-metric 1000 1 255 1 1500
note: if you use a network other then 0.0.0.0/0 then you must use the IP DEFAULT-NEWORK command to mark the network as a default network.
summarize to 0.0.0.0/0 – use this method if you want to provide remote sites with a default route.
note: a summary to 0.0.0.0/0 overrides a default route learned from any other routing protocal.
note: don’t worry about distribute lists because you are using this on an interface so it won’t be progate to the core
route ei 1
net 10.0.0.0
int s0
encap frame
no ip add
inter s 0.1 point-to-point
ip address 10.1.1.1
frame-relay interface-dlci 10
ip summary-address eigro 1 0.0.0.0 0.0.0.0
—————————————————————–
eigrp will load balance up to 4 equal cost paths. if you use max-paths then you can use up to 6 routes of equal cost
ex with unequal cost paths
path 1 : 1100
path 2: 1100
path3: 2000
path4:4000
ny default the router will place traffic on path1 and path 2. You can have the router use all 4 paths by using the VARIANCE command. VARIANCE is a multiplier.
eg.. to load balance with paths 1, 2 and 3 use variance 2 (1100×2=2200 which is higher then the metric of path 3.)
eg..to load balance with path 1,2,3 & 4 use variance 4 (1100×4 = 4400 which is higher then the metric of path 4.)
—————————————————————————————————————————————————-
when manipulating metrics always set the true bandwidth of the interface. The delay should always be used to influence EIGRP routing decisions.
————————————————————-
By default eigrp will accept is 100. You can set the max t0 220 with metric maximum hops.
——————————
When redistributing eigrp into ospf make sure you use the SUBNETS keyword.
router ospf 1
redistribute eigrp 1 subnets
note: When routes are redistributed into OSPF, only routes that are not subnetted are redistributed if the subnets keyword is not specified
—————————————————————————–
The metric value specified in the redistribute command supersedes the metric value specified using the default-metric command.
————————————————————
Troubleshooting.
When you ping 224.0.0.10 does the neightbor reply?
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Just keep in mind they may tell you to perform this load-balancing over X
number of paths, but the only variance value to fit this requirement will
actually cause you to exceed you path requirement. In that case you may
need a variance value AND a maximum-paths value.
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