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14 votes

What happens in the real world Internet - BGP and OSPF?

Typically, autonomous systems (ASNs) use an IGP (which can be OSPF, IS-IS or iBGP) so routers in their network know how to reach eachother. Networks connected to these routers and reachable through ...
Teun Vink's user avatar
  • 1,837
11 votes

If public IPs are pinned to a single AS, how does BGP anycast work?

An AS doesn't need to necessarily be constrained to a single physical location. When anycasting, you run routers in many physical locations, each peering with different ISPs as the same AS, ...
Shane Madden's user avatar
5 votes
Accepted

If public IPs are pinned to a single AS, how does BGP anycast work?

There is no requirement that IP addresses or Internet routes for a prefix come from a single AS. ASNs are assigned to organizations, and addresses are also assigned to organizations. Registrars like ...
dk1's user avatar
  • 166
5 votes
Accepted

Traceroute and BGP peering

Yes, it's possible if there was tunneling involved and the two end points are in different networks. You won't see the hops between the two tunnel endpoints then, just the end points itself. It's not ...
Teun Vink's user avatar
  • 1,837
4 votes

How to connect to a BGP network?

Answers: Yes, it's possible to connect to a BGP network with Ubuntu server. You'll need to run a special software, have a network card with at least 2 interfaces, and of course to have connection to ...
13dimitar's user avatar
  • 2,546
2 votes
Accepted

BIRD BGP Advertise Network with different gateway

Routing protocols, like BGP, don't advertise gateways. A gateway is a host concept. When a routing protocol advertises a prefix, it is saying to the other routers with which it shares the routing ...
Ron Maupin's user avatar
  • 3,273
2 votes

How to find which routing protocol a router is using. And if found how to test it

show ip route--command will give you the output of running protocol and routes on cisco routers, you can identify the which routing protocol is running on routers by its codes. Codes: C - connected, ...
user346467's user avatar
2 votes

If public IPs are pinned to a single AS, how does BGP anycast work?

This (and resources like this page) seems to imply a mapping of 1 public IP to 1 AS. Yes. That is true. However, anycast seems to work by advertising the same public ip address from multiple ...
TomTom's user avatar
  • 51.9k
2 votes
Accepted

Separating networks on 2 bgps from 2 ISP

I assume from your question you only really want to control inbound traffic to your 2 networks from the ISPs. You need to alter the routing decision for upstream networks, 2 ways you could do thist ...
c3st7n's user avatar
  • 136
2 votes
Accepted

how can I know since when has a BGP prefix been allocated?

The netblock the IP address 216.90.108.31 is in was originally allocated on 1998-09-24. The autonomous system number 23028 was registered on 2002-01-04. Their registration dates have no relation to ...
Michael Hampton's user avatar
2 votes

VPN between on prem and GCP: routes shared but ping doesn't go through

It's looks like a routing problem on-prem. I think, OP_VM doesn't have a route to 10.0.0.0/24 and as result send it to the default gateway DC Router Gateway and there it's dropped because DC Router ...
Serhii Rohoza's user avatar
2 votes

About MPLS label range

An MPLS label is a 20-bit field, so the range is 0 to 1048575. There is no set definition for values for a specific purpose, so every manufacturer does it differently. Cisco, among others, allows ...
Ron Trunk's user avatar
  • 2,179
2 votes
Accepted

Reached cloud router limits

There is a hard limit of Cloud Routers per VPC/Region and is 5. It is not possible to increase this limit If you are planning to choose another region to deploy your Cloud Router the considerations ...
arcabah's user avatar
  • 96
2 votes
Accepted

EdgeOS BGP routes received but not being injected

I think you need to enable ebgp multipath value of 4 Here I'm attaching you a configuration that could help you: $ show protocols bgp bgp 65501 { neighbor 10.1.255.254 { ebgp-multihop ...
miguelfrancisco85's user avatar
1 vote

VPN to Shared VPC in GCP incorrect BGP routes being chosen as best

I worked around this issue with just a simple AS prepend to the "remote" routes on the outbound route map, approximately this: router bgp 65001 neighbor 169.254.x.y route-map DISTtoBGP out ! route-...
Bryan Vukich's user avatar
1 vote
Accepted

How to create a group of servers listening on the same IP-address, allowing failover/takeover?

Instead of BGP use combination of haproxy (load balancer) with keepalived VRRP solution (solves VIP - Virtual IP). There is simple howto: dasunhegoda.com/how-to-setup-haproxy-with-keepalived/833/ ...
Jaroslav Kucera's user avatar
1 vote

Route-Distinguisher (RD) to import and export the prefixes?

Route distinguishers are not unique to customers. It only has to be unique on the router. Route distinguishers and route targets serve different purposes. Route distinguishers make prefixes unique. ...
Ron Trunk's user avatar
  • 2,179
1 vote

What kind of routes can be propagated to VPC route tables?

You can configure VPC route tables for route propagation such that VPN and Direct Connect/Direct Connect Gateway prefixes from the Virtual Private Gateway (VGW) populate the routing table. If you have ...
Jeff Loughridge's user avatar
1 vote
Accepted

VPN between on prem and GCP: routes shared but ping doesn't go through

After much testing and debugging, I have resolved the connection issue between GCP and on-prem. The below is the steps taken, and also considerations made while pinpointing the problem. Analyse ...
Ryota's user avatar
  • 121
1 vote
Accepted

Problems with RD, RT import and RT export in MPLS VPN and BGP

From what I've already understand, RD (route distinguisher) identifies the VRFs from a network that compose the same virtual network and change routing info between them. That’s not right. RD is ...
Ron Trunk's user avatar
  • 2,179
1 vote
Accepted

Under volumetric DDoS can I prevent ISP null-routing by turning NIC off briefly?

Short answer: not likely to help. Your ISP routes a range of IP addresses to you, not just a single IP. So the traffic will come to your data center regardless if the host is online or not. ICMP ...
Ron Trunk's user avatar
  • 2,179
1 vote

IP Transit Using GCP compute instance?

No, because Google won't onward announce your AS and prefixes.
SimonJGreen's user avatar
  • 3,245
1 vote
Accepted

can I still map an IP address to its ASN number when the last octet is masked?

As far as I am aware there is no theoretical or technical minimum/maximum size of the prefixes that can be assigned to an ASN so I'm not sure. (Practically of course larger networks and smaller ...
HBruijn's user avatar
  • 80.2k
1 vote
Accepted

Synchronize states of bridge interfaces

I wrote a script that checks interfaces against /sys to determine if they are bridge members and then bounce the bridge. VyOS uses netplugd to monitor interfaces and for some reason my script confuses ...
yakatz's user avatar
  • 1,243
1 vote

Synchronize states of bridge interfaces

I would run a script on the VyOS machines that checks the state of the upstream connection and then does ifdown/ifup on the other side as needed. The simplest way to do this is putting scripts in /...
Moshe Katz's user avatar
  • 3,182
1 vote

BGP advertising routes accross connected virtual networks

Use Vnet peering between AU and UK Vnets, which would ultimately help you in route advertising in both the ways and the communication between your Vnets would remain same. https://docs.microsoft.com/...
Venkataramana Reddy's user avatar
1 vote

BGP advertising prefixes

Ideally your ISP generates a filter based on the RIR information such that only your specific /25 is permitted via your BGP peering to them. The various registries (ARIN, RIPE, APNIC, etc) have ...
rnxrx's user avatar
  • 8,153
1 vote
Accepted

Dumping route changes from openbgpd

There are dump and log updates configuration options that may do what you want.
user9517's user avatar
  • 116k
1 vote

Bandwidth consideration of using AWS hardware VPN or Direct Connect?

Direct Connect should be first choice in case of high bandwidth requirement irrespective of the latency measurement because VPN setup indeed dependent on the public infrastructure used and may not be ...
C Singh's user avatar
  • 60
1 vote
Accepted

How can I make two routers to speak to each other when they both belong to two different subnet and AS?

With out "disable connected check command" also this scenario worked for me.Added a static route to neighboring route and achieved neighbor ship. R1# router bgp 200 no synchronization bgp log-...
shiras k a's user avatar

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