Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [bgp]

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

0
votes
1answer
14 views

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

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
19 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
16 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
97 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
23 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 ...
2
votes
1answer
23 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
49 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 ...
3
votes
2answers
107 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
36 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
28 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
73 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
70 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
100 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
33 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. ...
0
votes
1answer
56 views

Propagating 'trash' ASN, what happens?

This sounds crazy, but I'm analyzing the raw RIS BGP announcement dataset and I spot this announcement: BGP4MP|1543859911|A|198.32.125.181|51185|52.94.20.0/24|51185 9304 1161216244|INCOMPLETE|198....
2
votes
0answers
21 views

How do you specify BGP Authentication Key when using Verizon's Secure Cloud Interconnect?

I am trying to establish a Direct Connect Link using Verizon's Secure Cloud Interconnect service. I have established the connection in the Dynamic Network Manager on the Verizon side and the VIFs ...
0
votes
1answer
57 views

In one organization having two ISP which configured on fortigate firewall ? How can we do the failover for internet?

Organisation don't have AS number .As of now we are doing manually route for any ISP at a time. when default Internet link is go down that time making second link enable on firewall. I saw the some ...
1
vote
3answers
64 views

How is traffic forwarded though IXPs if route servers do not forward any traffic

while i was studying about IXP route-servers, i read that they do not forward any traffic. I get that a route server is a "control plane" entity and it is used for easier bgp peering. However, i ...
2
votes
1answer
56 views

Setting local preference in BGP

I am trying to set the local preference for this configuration To make a route from R1 to R4 via R3. That's how i configure R3 R3#conf term Enter configuration commands, one per line. End with ...
0
votes
1answer
75 views

Download Internet Routing Table

What is the best way to download a snapshot of the Internet's IPv4 routing table? I need check if IP addresses are routable. It needs to function offline, so a looking glass server won't work. I know ...
0
votes
1answer
54 views

Bad mask for loopback interface

I am trying to implement BGP session. I was given this table. When I try to configure loopbacks the first loopback works in the proper way R1(config)#interface loopback 0 R1(config-if)#ip *Mar 1 ...
2
votes
1answer
31 views

JunOS iBGP and return paths odd behaviour

I've got a somewhat basic iBGP configuration with a routing instance "global" between two Juniper vSRX's - each Juniper vSRX has an uplink of its own from a different transit provider with a default ...
1
vote
2answers
64 views

Gather the BGP data by using TCP connection on port 179

In order to gather the information shared between BGP peers, what port number should be used to connect using TCP (I am using 179, and don't see the connection being established)? Will I be able to ...
2
votes
1answer
80 views

Use case for two BGP ASNs?

I’m new to BGP and have a relatively simple question, or so I think it is for you BGP veterans. I would like to build two new seperate edge networks at my company; one for production services and ...
1
vote
1answer
26 views

All routes about a IP in my Router AS-PATH last AS number is Idle

I can not ping the IP 202.137.151.185 from my router. and in my router I show a IP's route, there gets the following information: admin@EE-MX-RE1# run show route 202.137.151.185 ...
6
votes
3answers
1k views

Why is the BGP base on TCP 1027 rather than 179?

Why is the BGP foreign address port 1027? I use BGP to connect Router1 and Router2, but when I show the TCP progress: Router1>show tcp brief TCB Local Address Foreign Address ...
4
votes
1answer
73 views

juniper advertising smaller subnets with a bigger static route in BGP

I have a /18 in RIB but I would like advertise smaller subnet in BGPfor specific reason to diff ISP etc. Is there a way to do it without creating a null route or static route. Is some way in policy ...
2
votes
1answer
79 views

Why do we need MPLS when implementing L2/L3 VPNs?

Yes, I know that MPLS doesn't care about L3 and higher levels and it is one of its features. But I do not really understand its role in L2/L3 VPNs. L2VPN - we are building xconnects to PE's AC. Why ...
2
votes
1answer
23 views

How can I see where BGP is advertising a given prefix? (Junos)

I'm working in a complex BGP environment on Juniper MX480s. We have many peers in various routing instances advertising prefixes to us, and then we advertise a subset of those prefixes to a subset of ...
6
votes
0answers
336 views

Cisco BGP Graceful Restart behavior

In our environment we generally have ASR-1000X-2s everywhere peering via iBGP/eBGP. These routers have no redundant RPs, hence cannot keep forwarding traffic while the router reboots or crashes. As ...
2
votes
1answer
93 views

Does the iBGP belong IGP?

We know the iBGP in the AS can transmit the BGP data, it running in the AS, is it belong IGP?
6
votes
2answers
111 views

Issues with Juniper MX-series iBGP routes

I have a simple setup: 2x Juniper MX-Series routers each having one uplink to a transit provider iBGP session between both routers (point-to-point) For testing purposes I've disabled the uplink from ...
5
votes
1answer
74 views

PP BGP Load Balancing with JUNOS

So we've got a couple of BGP upstream providers, whom both are providing us with their full internet routing tables. What we are now wanting to do, is utilize both providers, rather than just one ...
1
vote
0answers
23 views

How does BGP decide which prefix to advertise out of the prefixes in the routing table? [duplicate]

The ip routing table shows that I have 4 routes to reach 0.0.0.0/0. #show ip route 0.0.0.0/0 0.0.0.0/0, ubest/mbest: 4/0 *via x.x.16.6, [20/0], 2d, bgp-64500, external, tag 64500 *via x.x.17.4, [20/0]...
2
votes
1answer
152 views

Why use iBGP over eBGP?

Why would you use iBGP over eBGP. i.e why use a single AS with an RR over multiple AS's using eBGP. Is it simply for peering design simplification i.e large amount of devices all peering to a set of ...
3
votes
1answer
152 views

Config BGP policy for limit ISP path in Juniper MX 480 Router

Now we have a source IP14.135.4.0/24, we are involved in 5 different ISP, such as A, B, C, D, E. Now we want to access 14.135.4.0/24 not through the path of ISP B and ISP D, but through the other ...
0
votes
1answer
39 views

Routing an owned /24 IPv4 block to a single server [closed]

How would one go about routing a recently-purchased /24 block of IPv4's to a single server? The server is colocated in Zare.com, and the BGP session is already set up and announced.
1
vote
1answer
185 views

How to find a AS-SET of an asn?

How can we find the as-set of asn? For Example I have the asn:32934. I want the as-set?
1
vote
2answers
156 views

BGP with x2 sessions and x2 L3 VLANs - Please Explain

I am learning about Cisco BGP networking now and came across an interesting situation. In my examples, there was one which suggested that two VLANs were configured on Layer 3 in order to run two BGP ...
1
vote
1answer
109 views

How can I reduce latency to Australia from another country? [closed]

I often do a lot of work from the UK to destination networks in Australia be it voice calls or something more benign like gaming. Both of which work best with the lowest RTT possible. On average the ...
1
vote
1answer
87 views

Can i implement BGP flowspec

This question is for general information about BGP flowspec, Can i implement BGP flowspec to stop DDoS? RTBH isn't what we want because it blackholing all traffic, we want RTBH at Layer 4 level where ...
1
vote
1answer
42 views

Strange BGP routing issue between two public routers. Not able to see subnets

Having a strange issue can't seem to figure out what's happening. I got 2 routers running BGP. Router A is advertising 23.128.128.0/24 subnet and Router B is advertising 23.128.129.0/24. Routing is ...
5
votes
1answer
172 views

JunOS iBGP session not establishing

I have a test environment set up with two Juniper vSRX instances and a L2 network trunked between them and can reach each other on the IP addresses I'm trying to peer them on. vSRX 1 has an external ...
1
vote
2answers
175 views

Can we have multiple AS number in the same router?

Is it possible to have multiple AS number in the same router? Example: Routing-Instance A for AS100 and Routing-Instance B for AS200 ? Please share me some example or configuration.
0
votes
2answers
170 views

Leak default route to multiple VRFs while keeping VRFs isolated from each other

I'm working on a configuring stuff on a Cisco Nexus 3k based platform and trying to isolate different things into different VRFs which should not be able to talk to each other. Some of these VRFs ...
1
vote
2answers
114 views

Using a Public AS Number Internally

We have BGP between our network and our customers networks and so far each connection uses private AS numbers (on our end we use a different AS number for each connection) We recently got a public AS ...
2
votes
1answer
79 views

how to select the most optimized BGP Anycast combination with BGP as-path prepending

The question as following: Suppose I have 3 POP (Points of Presence) points, they have the same IP address and located at different countries, such as: USA, Japan, England. The three countries serve ...
2
votes
2answers
99 views

BGP new subnet announcement

I have above scenario where I got public IP subnet got from ISP 74.100.100.0/23 and i have configured eBGP and iBGP as you can see in diagram, I have configured those Public IP in HSRP my LAN side. ...
4
votes
0answers
58 views

mp_reach_nlri bgp Update with 4-byte Community ASN?

I am BGP peering with a Juniper OS router. When starting the connection, my system advertises 4-byte ASN capability, which is accepted by the Juniper router: Jul 28 00:33:00.664202 BGP RECV 4 Byte ...
5
votes
1answer
193 views

Max AS path to accept from peer?

I heard that once AS receives a BGP update that is longer than 50, it will be dropped. Is this true or just happens with some ISPs specifying that policy? I cannot find any evidence or official ...