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  1. My company have two ISP connections but we only use 1 for all our traffic and the other was is for backup situation. We were planning to buy a netgear router (http://www.netgear.com.au/business/products/security/FVS336G.aspx#tab-features). There are two WAN port and it has load sharing capability. Are you saying that in the configuration we will not be able to set 80% to ISP 1 and 20% to ISP2 and it will be 50/50 distribution only? and if we do want to send 80% trafic through 1 ISP and 20% through another we don't have an other option but to buy beefy routers to run BGP. Moreover, I heard that bgp is more about controlling incoming traffic flow from multiple ISPs to your network (you may be running multiple webserver in your network)rather than outgoing traffic from your network?

  2. Hi Rene! You write excellent articles about networking!

    I have just started learn BGP, and there is question that bother me. I attached screenshot from some site, and as you can this is wireshark capture. Router sends bgp packets "OPEN Message, KEEPALIVE Message" and "KEEPALIVE Message, KEEPALIVE Message". Meaning there are two messages in one packets. Why BGP process do that? I test that and in very beginning of bgp session initiation routers send "update message, update message" (meaning there are two update messages in one packet) to each other.

  3. Hi Lorenzo,

    Thanks, glad to hear you like it!

    That capture looks weird...I haven't seen it before and I can't find anything about it. Where did you find it?

    Seeing multiple update messages in one frame is normal but I haven't seen open + keepalive combined. Here's a wireshark capture I just did on two IOS 15 routers with external BGP:




  4. Hi Lorenzo,

    I took a look, with google translate I can get pretty far :slight_smile:

    About the update message...

    • When the path attributes for prefixes are the same then BGP will combine them in a single update message.

    • When the path attributes for prefixes are different then BGP will use multiple updates messages but they can be in the same frame.


    Take a look at these two wireshark captures. In the first one the path attributes are the same and in the second one they are different.

    BGP same path attributes

    BGP different path attributes

    Hope this helps.


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