All Questions
71
questions
0
votes
1
answer
180
views
Can you have multiple paths in BGP through different ASes?
In a course about networks in my university, we learnt about how in BGP routes, each AS chooses a single route to each IP prefix (though you may have multiple iBGP routes).
Meaning that in the ...
- 101
2
votes
2
answers
624
views
Is BGP always required when you have multiple ISPs?
I am trying to understand when is Border Gateway Protocol needed and I stumbled upon this question:
When is BGP needed?
The chosen best answer says:
You could peer with your service provider and ...
- 491
11
votes
1
answer
6k
views
How much RAM you actually need to keep whole global BGP routing table?
It seems that different sources claim very different RAM consumption for having whole BGP routing table information in RAM and having the router to correctly route the traffic.
According to ...
3
votes
3
answers
628
views
Multihoming with two 'good' providers - load sharing strategy?
We get two 100G links, one from each provider and our aggregate traffic is sub 100G. The rationale is one provider can fail and the other will pick up the slack with zero degradation. Our traffic ...
- 33
1
vote
1
answer
118
views
NAT cannot communicate with 2 network
I have configured BGP for routing and NAT for HQ and Branch. I can ping from windows / server to public IP and also Linux Mint ping to public IP. but, I cannot ping / communicate between network HQ to ...
1
vote
1
answer
813
views
BGP Best Path Selection Algorithm
According to this cisco document (https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13753-25.html), shortest AS_PATH is the #4 algorithm in the sequence to evaluate, out of 13 ...
- 121
0
votes
1
answer
129
views
BGP unnumbered on P2MP link
I'm wondering what will happen if BGP unnumbered session is configured on a link that has multiple routers on the other side which are both IPv6-capable and will both reply on RS and produce RA ...
3
votes
2
answers
3k
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 ...
- 1,237
0
votes
2
answers
123
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
0
votes
1
answer
371
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 ...
- 55
2
votes
2
answers
595
views
How does aggregate routes behave in BGP?
If a router received two BGP updates for the same prefix and both these updates are aggregate paths how do the router decide which one to take? Let us say that it needs to decide based on AS Path ...
- 31
0
votes
2
answers
123
views
How BGP guarantees same route for a forwarded packet?
In BGP all routers choose the best route to a single destination. So for Router A and destination D, A will forward the packet to the next-hop router (let us say router R) after knowing the best route ...
- 31
0
votes
1
answer
1k
views
Reasons for buying ASN for organisation that are located at single place
I see here that even some organisation/universities have bought ASN which are located at single location. What benefit they will get by buying ASN ? Is it compulsory to buy ASN if I have to buy some ...
- 103
0
votes
2
answers
151
views
What is benefit of allocating ASN to edge routers and not Ip addresses
What is benefit of allocating ASN to edge routers and not Ip addresses ? I mean we could have given these edge routers unique public ip addresses too ?
- 103
4
votes
2
answers
535
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).
...
- 905