Please help me to configure below network topology.

JAIRAM · ‎03-29-2020

Hi, can someone help me to configure this topology mean what should i configure like what IGP and EGP protocol and where to configure. please educate me for what all are technology will be configure in topology in best way.

please also let me know in how many way this can be configure.

Only i am getting confuse between the PE and CE routers configuration. how and what protocol should i use in best way.

Please help.

omz · ‎03-29-2020

Hi

There are quite a few options .. depending on the PE (ISP) static routing or any routing protocol between CE-PE. BGP is most common. ISP sending full BGP table or only default route.

If you are running IGP (RIP,EIGRP,OSPF) internally, usually, send a default route from CE to internal network and redistribute IGP into BGP.

You asked for how many different ways it can be configured - I guess someone can write a book on that.

But usually, its .. default route from ISP and you advertise your internal networks via redistributing IGP or static routes.

JAIRAM · ‎03-30-2020

If i redistribute igp route in bgp then all routes will propagate to PE then is this good practice for as network admin at costumer site.
Without sending full update of internal route to PE router, can i do.

Giuseppe Larosa · ‎03-29-2020

Hello @JAIRAM ,

PE nodes are managed by MPLS service providers

CE nodes are managed by enterprise IT stuff.

Your network scenario is a MPLS L3 VPN.

The CE nodes are configured in a standard way and they are not aware of being in a VPN,

Each CE node peers with the colocated PE node(S) send the local site routes and receive either a default route or the routes of all the remote sites that take part to the same VPN.

All the complexity is on the PE nodes that need to use multiple protocols to provide the service and among these protocols there is MP BGP.

So the easier choice for the service provider is to offer an eBGP session using BGP

Hope to help

Giuseppe

JAIRAM · ‎03-30-2020

can i have command scenario for complete this project from your side. if possible can you configure this topology and send back.

Giuseppe Larosa · ‎03-30-2020

Hello @JAIRAM ,

this is not the Cisco Learning Network we usually deal with real issues in real networks.

However, I can give you an advice I could open your net topology from this windows 10 PC and I think you are tasked with configuring the CE1 and CE2 devices.

Using eBGP and a private BGP AS like AS 65000 in your case you need to use AS 100

router bgp 100

! below commands are now default settings I report just for clarity

no auto-summary

no sync

network 10.10.10.0 255.255.255.0

network 10.10.11.0 255.255.255.0

network 10.10.12.0 255.255.255.0

network 10.10.13.0 255.255.255.0

neighbor 10.10.0.1 remote-as 101

+ one IGP like OSPF to be executed on CE1, CE2, CoreSw1, CoreSw2 you are fine

router ospf 10

network 10.10.0.0 0.0.255.255 area 0.0.0.0

This is enough the key point to remember is that the BGP network command can refer to routes learned in any way not only to connected routes. The exact prefix must be in the routing table ( for the no auto-summary command now a default).

There is no need to redistribute the IGP into BGP.

CE1 and CE2 can use a method to generate a default route into the site

router ospf 10

default-information originate

to be noted this command works if they receive a default route from the PE node.

Hope to help

Giuseppe

JAIRAM · ‎04-03-2020

Hi as you suggest i have configured EIGRP-100 on Core1&2, and CE1&2. eBGP between CE1&2 to PE. still i didn't advertise any inside subnet to ebgp neigbore and i don't want that my inside subnet would show to ISP. only i have enable default-information Originate to ebgp neighbore.

please see below configuration output.

CoreSW1#sh ip int br | ex un
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 10.10.10.1 YES NVRAM up up
FastEthernet0/1 10.10.11.1 YES NVRAM up up
Vlan10 10.0.0.1 YES NVRAM up up
Vlan11 11.0.0.1 YES NVRAM up up
Vlan12 12.0.0.1 YES NVRAM up up
Loopback1 11.11.11.11 YES NVRAM up up

CoreSW1#sh ip route

D 1.0.0.0/8 [90/158720] via 12.0.0.2, 00:30:09, Vlan12
[90/158720] via 11.0.0.2, 00:30:09, Vlan11
[90/158720] via 10.0.0.2, 00:30:09, Vlan10
D 2.0.0.0/8 [90/156160] via 10.10.11.2, 00:30:09, FastEthernet0/1
22.0.0.0/32 is subnetted, 1 subnets
D 22.22.22.22 [90/156160] via 12.0.0.2, 00:30:09, Vlan12
[90/156160] via 11.0.0.2, 00:30:09, Vlan11
[90/156160] via 10.0.0.2, 00:30:09, Vlan10
10.0.0.0/24 is subnetted, 5 subnets
C 10.10.10.0 is directly connected, FastEthernet0/0
C 10.0.0.0 is directly connected, Vlan10
C 10.10.11.0 is directly connected, FastEthernet0/1
D 10.10.12.0 [90/30720] via 12.0.0.2, 00:30:11, Vlan12
[90/30720] via 11.0.0.2, 00:30:11, Vlan11
[90/30720] via 10.0.0.2, 00:30:12, Vlan10
D 10.10.13.0 [90/30720] via 10.10.11.2, 00:30:13, FastEthernet0/1
11.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 11.11.11.11/32 is directly connected, Loopback1
C 11.0.0.0/24 is directly connected, Vlan11
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Vlan12

CoreSW2#sh ip int br | ex un
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 10.10.13.1 YES NVRAM up up
FastEthernet0/1 10.10.12.1 YES NVRAM up up
Vlan10 10.0.0.2 YES NVRAM up up
Vlan11 11.0.0.2 YES NVRAM up up
Vlan12 12.0.0.2 YES NVRAM up up
Loopback1 22.22.22.22 YES NVRAM up up

CoreSW2#sh ip route

D 1.0.0.0/8 [90/156160] via 10.10.12.2, 00:31:34, FastEthernet0/1
D 2.0.0.0/8 [90/158720] via 12.0.0.1, 00:31:34, Vlan12
[90/158720] via 11.0.0.1, 00:31:34, Vlan11
[90/158720] via 10.0.0.1, 00:31:34, Vlan10
22.0.0.0/32 is subnetted, 1 subnets
C 22.22.22.22 is directly connected, Loopback1
10.0.0.0/24 is subnetted, 5 subnets
D 10.10.10.0 [90/30720] via 10.10.12.2, 00:31:34, FastEthernet0/1
C 10.0.0.0 is directly connected, Vlan10
D 10.10.11.0 [90/30720] via 12.0.0.1, 00:31:35, Vlan12
[90/30720] via 11.0.0.1, 00:31:35, Vlan11
[90/30720] via 10.0.0.1, 00:31:35, Vlan10
C 10.10.12.0 is directly connected, FastEthernet0/1
C 10.10.13.0 is directly connected, FastEthernet0/0
11.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
D 11.11.11.11/32 [90/156160] via 12.0.0.1, 00:31:41, Vlan12
[90/156160] via 11.0.0.1, 00:31:41, Vlan11
[90/156160] via 10.0.0.1, 00:31:41, Vlan10
C 11.0.0.0/24 is directly connected, Vlan11
12.0.0.0/24 is subnetted, 1 subnets
C 12.0.0.0 is directly connected, Vlan12

CE1#sh ip bgp
Network Next Hop Metric LocPrf Weight Path
*> 99.99.99.99/32 10.10.0.2 0 0 101 i

CE1#sh ip route

1.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 1.1.1.1/32 is directly connected, Loopback1
D 1.0.0.0/8 is a summary, 00:35:21, Null0
D 2.0.0.0/8 [90/158720] via 10.10.10.1, 00:35:21, FastEthernet0/0
99.0.0.0/32 is subnetted, 1 subnets
B 99.99.99.99 [20/0] via 10.10.0.2, 01:08:00
22.0.0.0/32 is subnetted, 1 subnets
D 22.22.22.22 [90/156160] via 10.10.12.1, 00:35:21, FastEthernet1/0
10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
C 10.10.0.0/24 is directly connected, FastEthernet1/1
C 10.10.10.0/24 is directly connected, FastEthernet0/0
D 10.0.0.0/24 [90/30720] via 10.10.12.1, 00:35:25, FastEthernet1/0
[90/30720] via 10.10.10.1, 00:35:25, FastEthernet0/0
D 10.0.0.0/8 is a summary, 01:08:46, Null0
D 10.10.11.0/24 [90/30720] via 10.10.10.1, 00:35:22, FastEthernet0/0
C 10.10.12.0/24 is directly connected, FastEthernet1/0
D 10.10.13.0/24 [90/33280] via 10.10.10.1, 01:08:27, FastEthernet0/0
11.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
D 11.11.11.11/32 [90/156160] via 10.10.10.1, 00:35:22, FastEthernet0/0
D 11.0.0.0/24 [90/30720] via 10.10.12.1, 00:35:22, FastEthernet1/0
[90/30720] via 10.10.10.1, 00:35:22, FastEthernet0/0
12.0.0.0/24 is subnetted, 1 subnets
D 12.0.0.0 [90/30720] via 10.10.12.1, 00:35:17, FastEthernet1/0
[90/30720] via 10.10.10.1, 00:35:17, FastEthernet0/0

CE1#sh run | s eigrp
router eigrp 100
network 1.1.1.1 0.0.0.0
network 10.10.10.0 0.0.0.255
network 10.10.12.0 0.0.0.255
auto-summary

router bgp 100
no synchronization
bgp log-neighbor-changes
neighbor 10.10.0.2 remote-as 101
neighbor 10.10.0.2 default-originate
no auto-summary

PE#

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
10.10.0.1 4 100 60 58 12 0 0 00:49:49 1
10.11.0.1 4 100 59 59 12 0 0 00:49:51 1
PE#sh ip bgp
BGP table version is 12, local router ID is 99.99.99.99
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path
* 0.0.0.0 10.11.0.1 0 0 100 i
*> 10.10.0.1 0 0 100 i
*> 99.99.99.99/32 0.0.0.0 0 32768 i

PE#sh ip route

99.0.0.0/32 is subnetted, 1 subnets
C 99.99.99.99 is directly connected, Loopback1
10.0.0.0/24 is subnetted, 2 subnets
C 10.10.0.0 is directly connected, FastEthernet0/0
C 10.11.0.0 is directly connected, FastEthernet1/0
B* 0.0.0.0/0 [20/0] via 10.10.0.1, 01:09:49

PE#ping 10.0.0.1 source loo 1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.1, timeout is 2 seconds:
Packet sent with a source address of 99.99.99.99
.....
Success rate is 0 percent (0/5)

please help, from PE router inside network ( VLAN-10 ) is not reachable.