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
1
vote
2answers
350 views

How to block advertisement of a prefixes recieved from 1 BGP neighbor to another

I have a eBGP topology as follows: RTR1 ------ DUT ------ RTR2 (AS100) (AS200) (AS300) I do not want any routes sent by RTR1 to be advertised into RTR2 by DUT I do not know what exactly the ...
0
votes
0answers
14 views

BGP Example with Autonomous Systems [closed]

everyone! I am new to networking and want to understand how BGP works. Let's consider the following network: There are three AS, namely AS1, AS2 and AS3. The following intraconnections are established:...
3
votes
2answers
161 views

Is it possible to filter directly connected networks redistribute with BGP based on a peer basis?

Assume a simplified case in which router R1 is connected to two BGP peers: one eBGP peer and one iBGP peer. Is there a possibility to advertise directly connected routes only to one of them ...
3
votes
2answers
35 views

Why does Junos find multiple next hops only for the active prefix in case BGP multipath is enabled?

I have a Juniper router named r3 with one established eBGP session to router t1(172.16.0.14) and with second established eBGP session to router t2(172.16.0.18). BGP configuration of r3 can be seen ...
2
votes
4answers
66 views

Cisco N9K - Down an interface in response to another interface going down?

I currently have my transit providers plugged directly into my router. I really like this arrangement because when the ISP goes down this typically downs the interfaces which results in BGP peering ...
1
vote
0answers
27 views

How to redistribute BGP routes learned from AWS in one VR into another BGP running in another VR in Palo Alto firewall?

I have about 1000+ prefixes I am learning from AWS on Palo Alto through a BGP. This is on the secondary VR. Main VR is where my core routing is situated along with another BGP instance pointing to ...
0
votes
1answer
28 views

Make eBGP and iBGP equal in Juniper MX204

Apologize for the dumb question, I come from the server world. Our network admin is on holiday and I'm filling in. For the sake of simplicity, we have a fairly symmetric traffic pattern, what goes up ...
1
vote
1answer
29 views

Show 'all' routes to a given prefix on Juniper Router

Forgive me if I'm not using the correct terminology here but I'm on a Juniper MX204 router, call it router A. I'm receiving full table from my ISP. I do a show route, i.e. show route 1.1.1.1 and I ...
0
votes
1answer
33 views

BGP Authentication Key-Chain Between Cisco IOS XE L3 Switch (c9300-24S) and Juniper MX480 Router

Need to create a BGP authentication keychain between Cisco and Juniper devices. Need assistance with config commands for Cisco 9300-24S.
2
votes
1answer
58 views

Is it possible to withdraw a longer prefix without disrupting service via a shorter prefix announcement?

Using example IPv4 addresses for discussion, assume I have used BGP to announce to the Internet the prefix 192.0.0.0/16 from datacenter A, and I have also announced a longer prefix 192.0.2.0/24 (a ...
2
votes
1answer
62 views

BFD issue with BGP support on Cisco 9396PX

I have following BGP configuration and trying to reduce my convergence time with help of BFD but having hard time. router bgp 1111 log-neighbor-changes address-family ipv4 unicast network 22....
0
votes
1answer
31 views

Use ECMP to distribute traffic between two paths, one learned by eBGP and one learned by iBGP on a Cisco NX-OS switch

I maintain two cross-connected switches, R1 and R2, which both have a link to an external switch, R3. R1 and R2 both use eBGP to receive routes to various subnets behind R3. Additionally, R1 and R2 ...
0
votes
1answer
25 views

BGP - Active\Passive Setup, except one AS

I have two transit providers, A and B. The business has chosen to make provider A more attractive due to billing concerns (we get attractive bulk pricing from this global provider). This was done by ...
1
vote
2answers
102 views

EVPN/VxLAN border-leaf question

I have couple of question in above design where i have typical clos network design and my leafs are configured for Cisco vPC for redendency and anycast gateway and running OSPF for underlay and BGP ...
2
votes
1answer
134 views

Two Datacenter location with same BGP AS number

Currently we have DC-1 running eBGP with my ISP using AS:1111 and i have prefix 1.1.1.0/24 and using BGP Default route because we have only single ISP. Now we are opening new Datacenter in remote ...
0
votes
1answer
25 views

Can a leaf (mc-lag switch pair) connect to an uplink (spine : a single switch) using lag (not a route-only-port)?

By 'lag', I mean one port from each mc-lag peer connects to a port each on the uplink switch (consider this a single switch spine). The mc-lag is an active-active forwarding pair for L2 traffic (aruba'...
0
votes
2answers
82 views

BGP influence outbound traffic based on prefix

I have two router core1 and core2 connected with ISP router border1 and border2 using eBGP peer and i have 5 public subnect (/24). My ISP sending me default route instead of full BGP table. Question:...
1
vote
1answer
44 views

BGP Community Policy to only allow single Community tagged routes

I have a requirement to do a Cisco IOS-XR Route-policy to allow only routes that have a single community tagged and not allow routes with multiple community tags. I built a lab that has two routes: ...
3
votes
2answers
80 views

Advertising your prefix out of another ASN

We own a few blocks of IP addresses. At several distinct sites we currently advertise our own prefixes on our routers to our upstream transit provider. We are not anycasting. One /24 is originated ...
1
vote
1answer
45 views

Can people with an ISP access your network if it is on the Default Free Zone?

Let's say you have a router on the DFZ (despite costing an absurd ammount of money). Would your network work the same as if you have an ISP in terms of web hosting, etc? Can people still access your ...
1
vote
1answer
29 views

exabgp heathcheck session bgp

I've been trying to use exabgp. I know how to to issue command to the exabgp however i struggle to find whole list of commands the application accepts. With that I can't find a way to receive ...
2
votes
1answer
82 views

Brocade L2VPN Route Reflector

I am trying to create an MPLS VPLS network where the VPLS instances are auto-discovered via BGP L2VPN. The issue I'm currently facing is that the routes are not reflected and there seems to be no ...
0
votes
2answers
41 views

How can I tell which prefixes are being advertised?

Forgive me if this is a dumb question but I'm relatively new to the carrier networking world. We own a block of IP addresses, say a /18 and we advertise various /20s, /24s, /23s, etc all over the ...
1
vote
1answer
63 views

BGP Route Reflector

In the following configuration, INTERNAL1 and INTERNAL4 are RR and INTERNAL2 and INTERNAL3 are clients. I am not able to see the routes 20.1.1.0 and 10.1.1.0 on INTERNAL3 and 30.1.1.0 and 40.1.1.0 on ...
1
vote
0answers
40 views

In Bgp TTL security all control packets will have configured hop value?

Topology: loop(2.1.1.1) - routerA (192.168.1.2)--------- (192.168.1.1) routerB - loop(1.1.1.1) I have eBGP peering configured with a Multihop of 2 on both sides and static routes to reach loopbacks. ...
0
votes
1answer
160 views

isis redistribute bgp not working

I am having trouble getting route redistribution into ISIS working. It works from ISIS to BGP, but I can't get the opposite to show up. I am using IOS-XR Network has 3 routers: A----B----C A and B ...
1
vote
1answer
47 views

Extract upstream/downstream ASNs from BGP table path

I want to extract upstream and downstream ASN for any given ASN, for example: https://www.cidr-report.org/cgi-bin/as-report?as=AS4826&view=2.0 My goal at the end is to generate ASN route graphic ...
1
vote
1answer
53 views

eBGP failover without packet drops

I have core1 and core2 router peer with same ISP but distinct hardware and they are sending us default route. currently all in/out traffic going over to core1 and core2 is idle (standby), I have iBGP ...
2
votes
2answers
83 views

Get ASN Upstreams/Downstreams/Peers

I'm trying to gather the Upstreams/Downstreams/Peers of an ASN. Lets take for example AS8866, I run this query on the ripe API https://stat.ripe.net/data/asn-neighbours/data.json?resource=AS8866 ...
0
votes
2answers
41 views

Routing daemon vs router configuration

Which is the difference between a routing daemon and a router configuration? For example using BIRD you can set up a BPG session, but you can always set up a BGP session for example using a CISCO ...
1
vote
3answers
126 views

Active\Passive Routers w\ BGP

What I'm trying to do is take two routers, "A" and "B" where 'A' is the primary router. Just like with active\passive firewalls and HSRP I want to "float" the default gateway between either Router A ...
1
vote
0answers
15 views

Can BGP-LS provide an ip address as a node attribute when distributing IS-IS

I have an IS-IS network (all cisco) with a BGP router (cisco) that I am using to distribute the network link-state for monitoring / analysis. one thing I would like is to receive an IP address for ...
0
votes
1answer
53 views

Junos: how to change BGP MED for secondary node?

I have vSRX cluster, which announce some protected addresses over IBGP. Each node has two sessions with two routers. (I use ge-0/0/1 and ge-7/0/1 for that). I found that if fail-over happens, and ...
1
vote
2answers
75 views

Why isn't iBGP peer announcing external route it learned to its only peer?

I'm using VyOS to create a BGP lab. It has 6 routers, each in an iBGP pair, and 3 autonomous systems. Routers 1 & 2 - AS1111 Routers 3 & 4 - AS2222 Routers 5 & 6 - AS3333 All routers are ...
0
votes
1answer
39 views

Differences between BGP(routing protocols) and vpn mpls?

I am new to networking, so bear with me, 1-I wanted to clear my query: why do we need BGP or any routing protocols if we have vpn or wan technologies like mpls ? 2-Can't we just run bgp between two ...
0
votes
0answers
22 views

How can I use standard communities for route leaking?

I have a network something like this: R1_____Edge1____BB____Edge2_____R2 \____R3 R1: VRF BLUE (10:10) R2: VRF BLUE (10:10) R3: VRF RED (10:20) Edge1 and Edge2 has both ...
0
votes
1answer
52 views

Is it possible to determine the origin of a BGP withdraw message?

is it possible for an ASN in the BGP path to determine what ASN has been the originator and the cause of withdraw message?
-1
votes
1answer
34 views

Why doesn't BGP come up when no hold-time is defined? [closed]

Why doesn't BGP come up when no hold-time is defined? if defined, the BGP protocol comes up without any problem.
1
vote
1answer
59 views

Unexpected bytes in AS_PATH BGP attribute

I am parsing out the ASNs from several AS_PATHS. A majority of the attributes I encounter look like this one: [64, 1, 1, 0, 64, 2, 10, 2, 2, 0, 0, 23, 169, 0, 0, 50, 156, 64, 3, 4, 200, 40, 162, 202]...
0
votes
1answer
103 views

How is the MD5 hash calculated in BGP?

The RFC is very superficial on the implementation details. What is the injective function being used? https://tools.ietf.org/html/rfc2385 MD5 digest is produced by applying the MD5 algorithm to ...
0
votes
1answer
44 views

Difference between step 3 and step 5 of BGP route selection process?

Step 3: Locally injected routes (Locally injected is better than iBGP/ eBGP learned) Step 5: Origin Prefer I over E. Prefer E over ? I went through lot of articles on the internet but not able ...
0
votes
1answer
79 views

Traveling Salesman Problem (TSP) applied to network routing protocols? [closed]

Is this very common for larger enterprises that have many thousands of servers to use something like ant colony or similar algorithms to work together with network routing protocols like BGP to solve ...
0
votes
1answer
219 views

EIGRP to BGP to EIGRP

I would like to ask if it is possible to implement eigrp routing sent through bgp? I wanted to route from PC-1 to PC-2 using EIGRP. The connection between all of the three routers are through BGP ...
0
votes
0answers
12 views

Static routes use redistribute command or network command? [duplicate]

Apologies if this has been asked before, but quick question I have a router, actually a L3 switch that is running bgp. This switch has a bunch of static routes that are redistributed into bgp. ...
1
vote
2answers
361 views

Internet Scale Routing Table Size

In the link below, it is said that there are near one million prefixes for IPv4. https://bgp.he.net/report/netstats I want to know that it is a must for ISP routers to cache all these million IPv4 ...
0
votes
3answers
161 views

Single-homed connection to ISP without NAT feature

Is it possible to connect my private network to the ISP router without a Network Address Translator (NAT) feature enabled on my router? As I understand, in a single-homed scenario connection to ISP, ...
1
vote
0answers
44 views

Is there a way to check which routes are matched by a term in a routing map?

I have created a prefix-list and I am using it in a route-map. However, my route-map is not working as I expect it to work. ip prefix-list LIST_A seq 5 permit 10.20.20.0/22 ge 32 route-map A-B-OUT ...
2
votes
1answer
211 views

How to read a BGP table?

I have come across BGP looking glass where I can see the routing table for public routers. Please find below a public entry: BGP routing table entry for 78.97.0.0/16 Versions: Process ...
1
vote
2answers
71 views

BGP rule to avoid given ISP?

Is it possible to have a rule/policy in BGP to avoid a given ISP for the traffic? Ex.: traffic from the USA should touch middle east ISPs if the target/source is not from/to there. I am not sure ...
0
votes
1answer
36 views

What are the current security issues S-BGP has?

The question is explained in full in the title. I wish to know what the security issues are when deploying S-BGP. Thank you in advance!

1
2 3 4 5
12