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IP ROUTING

fmugambi
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Hello guys, below is my topology,

fmugambi_0-1716902477086.png

I have added internet fw  and introduced ISP on site B.

Before site B resources/ servers would go via mpls to site a to access internet.

I introduced the above to make each site use its own isp respectively.

I ran to challenges, site b resources were not able to get to their isp/internet, until i introduced " ip route 0.0.0.0/0 sitebinternetfw interface. --> which works but causes some issues.

is there a way, to manipulate just internet traffic for site b resources without introducing static entries? and not affecting site a and b from communicating with each other?

64 Replies 64

some prefix is learn via OSPF other is direct connect to R1 and hence same as previous 
you need 
redistribute connect into bgp to make 10.185.40/80.0 to advertise 
MHM

since R1  has ospf which has connected redistributed to it, then ospf redistributed to bgp? this is not enough?

i have to redistibuted the connected again on bgp?

fmugambi_0-1717677155915.pngfmugambi_1-1717677190772.png

 

since R1  has ospf which has connected redistributed to it, then ospf redistributed to bgp? this is not enough? Yes

You need to redistribute connected into bgp 

MHM

fmugambi
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fmugambi_0-1717676178229.png

what if i remove the static configuration domain from bgp border routers, r3 in this case. make r3 have ospf with r5.

see now r3 does not have any static route on its rib/fib.. how do i proceed now letting it know static route on r6?

fmugambi_1-1717676278902.pngfmugambi_2-1717676310574.pngfmugambi_3-1717676333390.pngfmugambi_4-1717676352283.png

 

in R5 do 
redistribute static into ospf 
in R3 do 
redistribute ospf into bgp ONLY no need any more need redistribute static into bgp in R3 since now R3 know the prefix via ospf 

MHM

fmugambi_0-1717679785254.png

fmugambi_1-1717679908755.png

this is done, but r1 does not learn any bgp routes from r3.

can I see 

show ip bgp 

in both R1 and R3 

MHM

fmugambi_0-1717680839388.pngfmugambi_1-1717680866748.png

 

I will focus on 10.185.45.0/24 prefix here OK 
it must advertise by R3 to R1 
NOW 
show ip bgp neighbor <<- in R3
I need to see route-map you use in bgp not only prefix <- in R3

MHM

fmugambi
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R3#sh ip bgp neighbor
BGP neighbor is 102.69.239.201, remote AS 64512, external link
BGP version 4, remote router ID 172.16.20.1
BGP state = Established, up for 00:00:23
Last read 00:00:23, last write 00:00:23, hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
Route refresh: advertised and received(new)
New ASN Capability: advertised and received
Address family IPv4 Unicast: advertised and received
Message statistics:
InQ depth is 0
OutQ depth is 0

Sent Rcvd
Opens: 1 1
Notifications: 0 0
Updates: 0 0
Keepalives: 1 1
Route Refresh: 0 0
Total: 2 2
Default minimum time between advertisement runs is 30 seconds

For address family: IPv4 Unicast
BGP table version 1, neighbor version 0/0
Output queue size : 0
Index 1, Offset 0, Mask 0x2
1 update-group member
Inbound soft reconfiguration allowed
Outbound path policy configured
Route map for outgoing advertisements is ROUTES-OUT
Sent Rcvd
Prefix activity: ---- ----
Prefixes Current: 0 0
Prefixes Total: 0 0
Implicit Withdraw: 0 0
Explicit Withdraw: 0 0
Used as bestpath: n/a 0
Used as multipath: n/a 0

Outbound Inbound
Local Policy Denied Prefixes: -------- -------
Total: 0 0
Number of NLRIs in the update sent: max 0, min 0

Address tracking is enabled, the RIB does have a route to 102.69.239.201
Connections established 1; dropped 0
Last reset never
Transport(tcp) path-mtu-discovery is enabled
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Connection is ECN Disabled, Mininum incoming TTL 0, Outgoing TTL 1
Local host: 102.69.239.202, Local port: 27347
Foreign host: 102.69.239.201, Foreign port: 179
Connection tableid (VRF): 0

Enqueued packets for retransmit: 0, input: 0 mis-ordered: 0 (0 bytes)

Event Timers (current time is 0x23960):
Timer Starts Wakeups Next
Retrans 3 0 0x0
TimeWait 0 0 0x0
AckHold 1 0 0x0
SendWnd 0 0 0x0
KeepAlive 0 0 0x0
GiveUp 0 0 0x0
PmtuAger 1 0 0xADE8C
DeadWait 0 0 0x0
Linger 0 0 0x0
ProcessQ 0 0 0x0

iss: 320437820 snduna: 320437893 sndnxt: 320437893 sndwnd: 16312
irs: 1213698146 rcvnxt: 1213698219 rcvwnd: 16312 delrcvwnd: 72

SRTT: 105 ms, RTTO: 1593 ms, RTV: 1488 ms, KRTT: 0 ms
minRTT: 76 ms, maxRTT: 348 ms, ACK hold: 200 ms
Status Flags: active open
Option Flags: nagle, path mtu capable
IP Precedence value : 6

Datagrams (max data segment is 1460 bytes):
Rcvd: 4 (out of order: 0), with data: 2, total data bytes: 72
Sent: 4 (retransmit: 0, fastretransmit: 0, partialack: 0, Second Congestion: 0), with data: 2, total data bytes: 72
Packets received in fast path: 0, fast processed: 0, slow path: 0
fast lock acquisition failures: 0, slow path: 0

Updates: 0 0 <<- no update send receive 
can I see the route-map you use 
not only it prefixs list

MHM

fmugambi
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seems i dont have a route map configured.

let me configure it.

apologies.

Dont worry 
we here support each other 
take your time 
ask more before apply commands in real network 
goodluck 

MHM

fmugambi_0-1717750354790.png

after adding route-map, it worked.

but stil r1 does not know the 172.16.57.0/24 network. i left it out of r3 prefix-list, since i have a real production evn where lots of clients with /32 terminate to a ipsec vpn.

how do i make r1 learn 172.16.57.0/24 network via r3 via bgp ?

 

did you include it in prefix list you use in route-map ?

MHM

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