Questions tagged [bgp]

BGP is Border Gateway Protocol, used on the internet both inside of and in between networks.

Filter by
Sorted by
Tagged with
4
votes
1answer
51 views

Regarding Administrative Distance

Different vendors use different Administrative distance for the same protocol.For example, in a Cisco router, the eBGP, AD value is 20, whereas in Arista routers, it appears different(i believe, 200). ...
9
votes
2answers
826 views

Does anycast addressing add additional latency in any way?

Does anycast addressing, in itself, add any additional latency to network connections? Specifically, if you had two servers located in the same data center that had extremely similar routes/number of ...
3
votes
1answer
58 views

BGP | Advertise a summary prefix out to customer location

I don't know what I should be using for this or how I should go about it. In my lab where I am testing out the BGP configs that I've learned I want my ISP topology to have a summary prefix for the ...
2
votes
0answers
49 views

Route Reflector not reflecting BGP-LU (Labelled Unicast) prefixes

I was reading about the Inter-AS MPLS VPN Option C from book ' MPLS in the SDN Era' . In it , the author establishes the BGP-LU peering between PEs and ASBRs and between RR and ASBR only.No BGP-LU ...
0
votes
1answer
22 views

Whether the anycast nodes can not in the same AS, and whether the different AS can pronounce the same IP segment?

The Anycast realize is through annunciate the same IP address in the different node using BGP protocol. you see the Server A and Server B use the BGP annunciate the same IP address 10.0.0.1. There ...
2
votes
2answers
85 views

BGP multi-path using loopback

I have above scenario where i have multiple PATH for my BGP so i have to setup loopback interface to make it ECMP routing on both path. I have cisco nexus switches and following is my first router ...
1
vote
1answer
73 views

How does IP assignment work for servers and data centers

If I had an IP address (for example bought range for my company), and 2 ISPs fibres, how would it be possible to set my network card to have same IP adress accessible from both connections? (know its ...
5
votes
2answers
814 views

BGP convergence issue

I have 2 different carriers on my Cisco 2921 router and I have set weight to 350 for my first carrier to force it for my outbound traffic, and I set second carrier weight to 300. I am receiving BGP ...
3
votes
2answers
97 views

Regarding eBGP Multipath

In one of the blogs, i read: "Unlike most routing protocols, BGP only selects a single best path for each prefix. It doesn’t do ECMP (Equal Cost Multi-Path Routing) by default but it is possible to ...
1
vote
0answers
28 views

How to get traffic to take BGP route if not matched in PBR?

I am a newbie to BGP and have an ASR1001x router (172.16.0.3), I'm forwarding an ACL to a second router (172.16.0.1) while I try to get BGP working on this one for a specific testing prefix-list ...
2
votes
2answers
58 views

Hub-Spoke communication with BGP

I'm trying to establish connectivity between Hub and Spoke locations of same enterprise with same AS using BGP. Within DC (hub) iBGP and OSPF is used and eBGP is established between Spokes and MPLS ...
2
votes
2answers
116 views

No route to host for IPs in same subnet being routed by bgp

I have set up BGP to do some custom routing for a subset of addresses in the range 192.168.1.0/24. I have verified that the BGP is working by testing ping/curl on a different host in a different ...
2
votes
2answers
93 views

Running iBGP without IGP

Given following setup: Configuration of the routers is very straight forward. Router BGP1: interface Loopback0 ip address 1.1.1.1 255.255.255.255 ! interface Loopback9 ip address 9.9.9.9 255.255....
1
vote
1answer
41 views

VPLS how to signal CE facing interface failure

Hello, I have a BGP-based VPLS setup with one CE machine being multi-homed multi-homing works if i for example shut the active PE or i somehow disturb the connection between my PEs... that ok but ...
0
votes
0answers
21 views

How to force client side HSRP interface to go into standby when internet is not reachable [duplicate]

I have a VIRL setup in which the client router is connected to a client switch that connected to two provider switches that have HSRP configured for the client gateway. The two switches are in an OSPF ...
2
votes
1answer
35 views

H-VPLS application with different types of VPLS

so ive been digging around VPLS for a while and i have come across a term H-VPLS. My knowledge is: VPLS can be signalled using LDP (manual or autodiscovery) or BGP (autodiscovery). H-VPLS: ...
0
votes
1answer
79 views

How to change AD on Juniper router?

I have this route on my Juniper Router and some destinations have two routes: OSPF and BGP. I want to change the administrative distance for the BGP route so that it will be smaller than the OSPF ...
1
vote
1answer
70 views

How to explain that a route has two different AS numbers?

I have a question about the AS path, see the below example where I show the route 114.114.114.114. This shows several BGP routes. See the fist route item. The AS path is 4809 4134 I, I want to know ...
0
votes
1answer
59 views

Can not use `update-source` in bgp neighbor command in Cisco Packet Tracer

In my Cisco Packet Tracer, I have a ISR4321 router: Router1(config-router)#neighbor 12.0.0.2 update-source lo0 ^ % Invalid input detected at '^' marker. I ...
0
votes
1answer
120 views

What's the meaning of `State` and `PfxRcd`?

When I execute the show ip bgp summary, I get the bellow data: Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 12.0.0.2 4 200 199 190 12 0 ...
2
votes
1answer
292 views

What's the commands of Cisco query bgp neighbor table, bgp table and router table?

In the AS router, I want to query its bgp neighbor table, bgp table, and router table. what's the commands of them?
3
votes
3answers
294 views

Why the last AS PATH item always is `I` or `?`? [duplicate]

you see my snapshot from m Juniper Router, I want to find the routes of 114.114.114.114, but there always get Idle or a ?, why:
5
votes
3answers
92 views

Why do all the intermediary routers need to run iBGP without tunneling?

I'm trying to understand the configuration behind iBGP - I understand you can run full mesh to prevent loops, run confederation or route reflectors, if you don't want full mesh, else run tunneling ...
4
votes
1answer
188 views

What does “Allow AS in” do in BGP?

When configure BGP in a SDN product, i saw there is an option to enable "Allow as in", could anyone know what is it!
0
votes
0answers
61 views

What's the meaning of `%BGP-3-NOTIFICATION: sent to neighbor 12.0.0.1 6/0 (unsupported) 0 bytes `?

In my Router's loopback interface, I configure the following IP address: Router2(config-if)#ip address 2.0.3.2 255.255.255.255 Router2(config-if)# %BGP-3-NOTIFICATION: sent to neighbor 12.0.0.1 6/0 (...
0
votes
1answer
47 views

My BGP router does not advertise configured prefixes

I have two Routers, which are Router1(BGP 100) and Router2(BGP 200), they have set up BGP neighbor for each other: this is my Router1's BGP configuration: ! router bgp 100 bgp log-neighbor-changes ...
0
votes
1answer
62 views

Why Cisco BGP neighbor command need the remote-as number?

When I in my Router2 add a neighbor, the bellow is my command: Router2(config-router)#neighbor 12.0.0.1 remote-as 100 you see, I need write two params, one is neighbor address, and the other is its ...
4
votes
1answer
235 views

Advertise all static route except the default gateway with Juniper SRX firewall

With the following policy, all static routes are advertised via BGP to my neighbor: root@Nitrogen# show policy-options policy-statement bgp-export-policy { term export-statics { from ...
0
votes
1answer
35 views

Cisco create BGP connection, do we need two direction's neighbor command?

I have two routers like bellow: in the Router1, I configured like bellow: ! router bgp 100 bgp log-neighbor-changes no synchronization neighbor 12.0.0.2 remote-as 200 network 1.0.0.0 mask 255....
3
votes
3answers
98 views

Why can the BGP protocol be implemented across routers, but the OSPF protocol can only be implemented direct connected routers?

Why can the BGP protocol be implemented across routers? But the OSPF protocol can only be implemented on directly connected routers? Is the OSPF protocol based on IP? we know the BGP is based on ...
2
votes
1answer
34 views

Juniper router how to check the BGP process port?

Juniper router how to check the BGP process port? If I have a router with IP address 12.12.21.1, we know it run a BGP process, which use TCP 179 port as default. How can I check if port 179 is ...
3
votes
2answers
197 views

How to understand the output below from BGP?

I don't understand some data of the show route: admin@MX-RE0# run show route 36.250.236.6 inet.0: 736608 destinations, 806660 routes (736608 active, 0 holddown, 7 hidden) + = Active Route, - = Last ...
6
votes
1answer
291 views

Can non-recursive BGP route be used to determine next-hop for recursive BGP route?

In BGP recursive scenario, the recursive route is taking an unexpected next-hop. Here is the routing table: S* 0.0.0.0/0 [10/0] via 10.10.10.1, wan B 172.16.5.0/24 [20/0] via 172.80.80.1, MPLS, ...
0
votes
0answers
29 views

How to properly setup graceful-shutdown community

I'm trying to setup graceful-shutdown community but it looks I cannot make it working. community-set comm-graceful-shutdown 65535:0 end-set ! route-policy SOMEIX-IN ! tried set local-preference 0 ...
2
votes
1answer
164 views

Can two networks with the same subnet be connected to the same router in different VRF?

Let's say I have the following four networks: Network A: 10.0.1.0/24 Network B: 10.0.0.0/24 Network C: 10.0.1.0/24 Network D: 10.0.0.0/24 I would like to connect networks A and B together, and do ...
6
votes
3answers
2k views

Can I announce prefix 161.117.25.0/24 even though I don't have all of /24 IPs?

I'm managing one BGP router, under the router I'm trying to announce the following IP prefix:161.117.25.0/24. But the problem is that some of the IP addresses were borrowed by other AS(Autonomous ...
0
votes
1answer
32 views

Why does my route-map blackhole some equally specific routes? [closed]

I have a challenging situation. I have two routers, in VIRL, sharing routes via BGP and OSPF I am attempting to remove the "network 0.0.0.0 255.255.255.255 area 0" from my OSPF process. I have tried ...
0
votes
1answer
76 views

Connecting eBGP and iBGP routers in Quagga

I am trying to run intra and inter-domain routing using Quagga. I like to announce a prefix from AS7 and I like AS6 receive it and send it to AS2(as shown in the attached topology). I know for intra ...
0
votes
1answer
25 views

local pref question

i have a cisco router with 6 bgp peers, 4 bgp peers is from out ip transit's and i am receiving full routing (bgp) table from them. 2 bgp session is over GRE tunnel. and i am receiving 1.1.1.0/24 and ...
4
votes
1answer
119 views

How long the EBGP peer convergence time

We are using Anycast, and I plan to implement the "nearest access" by appending myself AS path to impact my peer BGP routers. For example I have two POPs(they are same ip), Pop1 in London and POP2 ...
0
votes
0answers
44 views

Understanding RIB and Update data from RouteViews

Can someone walk me through some RIB data from RouteViews? I'm having trouble understanding how to make sense of it. The main thing I need to figure out is what part of the RIB entry can be used to ...
3
votes
1answer
51 views

Explanation of repeated ASN in an AS path from a RouteViews file

From the RouteViews RIB files, I was looking at the snapshot from Nov 06, 2017 at 18:00 UTC. This has to do with this BGP routing misconfiguration -- https://dyn.com/blog/widespread-impact-caused-by-...
4
votes
2answers
106 views

Juniper SR300 maximum BGP routes

I've got a Juniper SRX300 which i'm using to connect to 2 BGP peers. The documentation i've read says this SRX only supports 300,000 BGP routes, so for each peer I created an import policy (based on ...
4
votes
2answers
212 views

VXLAN / EVPN Types

Looking into EVPN and the route types (type 2 and 5) is my understanding correct. In terms of their placement into the relevant forward tables upon the device. EVPN Route Type 2: MAC/IP Advertisement ...
3
votes
2answers
76 views

JunOS Use iBGP route over OSPF route

Hello i have an issue where my Juniper router doesnt advertise BGP 10.255.255.4/32 to a neighbor because in inet.0 it is not issued as the best route root# run show route table inet.0 inet.0: 11 ...
0
votes
1answer
39 views

how to change a BGP path in juniper?

How to change the selected BGP route? I show the route 43.242.33.39, there shows 3 GBP paths. but I can not ping the ip(43.242.33.39). and can not traceroute it. how can I do with this?
5
votes
1answer
149 views

BGP - Advertise VRF routes

I have a router with a Global Routing Table (GRT), and a VRF. My end goal is to advertise to my eBGP neighbor my VRF routes. I have actually successfully done it by using address-families (ipv4, ...
3
votes
1answer
231 views

EVPN/VXLAN Flood and Learn

With the original VXLAN spec (RFC) there was no control plane. But Flood and Learn was used via either IR or multicast head-end replication. EVPN was then introduced as the control plane. My ...
1
vote
1answer
188 views

BGP Juniper not reflecting to Cisco?

I am really new to working with Junipers and I am struggling a bit with Route Reflector configuration. I have 3 routers Cisco-Juniper-Juniper2 here is my config: Cisco: router bgp 100 neighbor ...
0
votes
1answer
59 views

Regarding ECMP hashing

Assume we have a following topology. R1 represents Router1, R2 represents Router2, R3 represents Router3 and R4 represents Router4. Src represents the source Server. Dest represents the destination. ...