1 Routing Simulations – Zebra Routing Software Eric Ciocca Dimitris Zacharopoulos

2 Overview Current Routing simulators Routing Software Benefits of simulators Limitations Testing the two software packages Conclusion

3 Current Routing Simulators Java SSFNet (SSF) –Supports BGP (among others) –Runs in Java NS-2 –Multicast, various algorithmic routings Cnet –Simulates general hosts/routers

4 Routing Software Regular Routers –I.O.S. (Cisco’s Operating System) Under Unix O.S. –In.routed (typical unix routing daemon) –Gated (Another unix daemon) –Zebra Under Windows OS –Integrated routing service

5 Routing Software (cont.) Unix Routing Software –Routed supports only RIP and static routes –Gated Static, RIP, OSPF, BGP 4, IPv6 Difficult configuration –Zebra BGP, RIP, RIPng, OSPF v 2, v 3, IPv6 Easy CLI, just like Cisco’s IOS

6 Zebra Routing Software Zebra makes your computer a router! –And a Gateway router too!! Benefits –Test new configurations New routing policies New protocols –Don’t disturb the production network –Use cheap PCs instead of expensive routers

7 Zebra Architecture BGPdRIPdOSPFd Zebra routing manager UNIX Kernel

8 Zebra features Features –Can handle unlimited # of Interfaces –One process per one protocol –Route Server & Route Reflector integrated –Multithread based technology –Policy control and filtering

9 The testing setup For our experiments we use: –2 Solaris with two Ethernet cards each –1 Cisco 2514 –Zebra version 0.89 Cisco Router AS400 Solaris Router B AS2525 Solaris Router C AS2525

10 Concept behind our test bed We want to compare the communication: –Router – zebra –Zebra – zebra –Router – router What to test: –Bgp 4 sessions, (routing updates, keepalive) –Route reflection –Default route propagation

11 Software simulation of BGP4 BGP simulation is a part of the SSFNet simulator –Allows simulation of arbitrarily sized networks –Incorporates most major features of BGP Most recently added, route reflection

12 Benefits of BGP Simulation We are not restrained by physical hardware –We are able to simulate very large, elaborate networks –No purchasing of routers to test layout –No modification of real routers to test changes in policy

13 SSFNet Specifics SSF=Scalable Simulation Framework SSFNet Supports multiple protocols (OSPF, BGP4, TCP, IP, custom) and network entities (NIC, host, router) Java SSFNet requires JDK1.2 or higher DML models are system independent Requires a discrete-event simulation kernel –A simulated one is available for free from Renesys

14 Simulated BGP4 Features iBGP / eBGP are both supported –iBGP supports route reflection –Does not support confererations Policy (route filtering) is mostly implemented but untested Update handing is fully implemented

15 What we have accomplished For the physical simulations: –Successfully achieved BGP peering between all machines –Added some static routes –Exchange routing information –Debug the protocols used –Used both eBGP and iBGP

16 What we have accomplished For the software simulations: –Successfully simulated BGP peering between virtual routers –Exchanged routing information between BGP peers –Used both eBGP and iBGP –Simulated route reflection in a medium- scale network

17 A quick example Route propagation from left to right X XYZ

18 SSFNet Results ~# ~# = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ~# PROPAGATION Validation Test: successful if five steps printed below ~# = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ~# ~# 1. AS X: sent route advertisement to AS Y ~# 2. AS Y: received advertisement from AS X ~# 3. AS Y: sending update to AS Z ~# 4. AS Z: received update from AS Y ~# 5. AS Z: route added to forwarding table ~# *** TEST SUCCESSFUL *** ~# | 1 timelines, 5 barriers, 126 events, 365 ms, 1 Kevt/s

19 Real network results

20 TO DO Route reflections –Some problems with IBGP behavior Override kernel routes –We are unable to make changes to routes that were installed by the kernel before we run zebra –Need to check if this is regular behavior Test bad gadget if we find more equipment..

21 Conclusion Zebra is far better than any other routing software One process for each protocol Dynamic configuration changes Interactive queries (supports bgp regexp table lookups)

22 Conclusion So far, the SSFNet simulator behaves the same as a “real” network of BGP peers Java SSFNet is a portable, lightweight simulator which can replace real-router modification for network experimentation

23 Thank You! Zebra – SSFNet –