Using Packet Tracer to prove dual-colo resilient design, but getting unexpected BGP results
I have a design (pictured in the attached file "BGP_Testing.png") for a dual-colo service, with resilient network, using a single Internet feed at each ColoA and ColoB and a dedicated cross-connect between the two sites. The internal, inter-site routing is using OSPF, as we wanted a vendor-agnostic protocol and the ability to join non-Cisco kit into the LAN, without a routing service re-design. The external routing is done via BGP, from our CP to the ISP's PE, who then handles the rest.
The IP ranges I'm testing with are as follows: -
Platform Subnet: 10.0.220.0/23
Each site is BGP advertising the main platform subnet /23 prefix and a site-specific /24 prefix and this works OK when both Internet feeds have always been up.
I am testing this arrangement, using Cisco Packet Tracer v5.3.3.0019 like this: -
1: Normal Routing
Test: ping PC1-ColoA from "Remote PC"
Desired Result: traffic should travel the most logical route to PC1-ColoA, via ISP-A & R1-ColoA and back the way it came
2: ColoA Internet Failure
Test: "shutdown" on the R1-ColoA's external interface (while pinging PC1-ColoA from "Remote PC")
Desired Result: traffic should start to arrive via ISP-B -> R1-ColoB -> R2-ColoB -> R2-ColoA and back the way it came
3: ColoA Internet Feed Returns After Failure (weird results I think)
Test: "no shutdown" on the R1-ColoA's external interface (while pinging PC1-ColoA from "Remote PC")
Desired Result: traffic should start to arrive at PC1-ColoA, via ISP-A & R1-ColoA and back the way it came
However, the route to 10.0.220.0/23 seems to be favoured over the 10.0.220.0/24...
Also, when the R1-ColoX external interface comes back up after testing, I don't see an immediate BGP neighbor relationship and associated route advertisements. Is this meant to be quite quick, or is there some sort of set period I have to wait, while biting my nails?
I need to know if this is just a Packet Tracer weird thing, or if it's a fundamental flaw in my design.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.