1. Connect. Communicate. Collaborate mcview – A tool for visualising and debugging multicast Stig Venaas, UNINETT TNC 2008, Bruges, May 21 st

2. Connect. Communicate. Collaborate Overview We present mcview which is a tool for visualising and debugging multicast We will discuss the following: –Multicast management and the need for new tools –What mcview tries to solve –Architecture and current state of mcview –How you can deploy and use mcview

3. Connect. Communicate. Collaborate Multicast management IP Multicast is quite complicated –In particular routing protocols like PIM-SM –Few people know how to track down and fix multicast problems –Debugging requires considerable time from highly trained people –Multicast management is expensive One reason why many ISPs do not provide it The need for management tools –Aid non-experts in performing debugging –Quicker detection and isolation of problems –Help with monitoring How many are receiving, which content is most popular etc

4. Connect. Communicate. Collaborate Interdomain multicast management The situation is even more difficult for interdomain multicast –In particular NRNs have been providing interdomain (internet) multicast for many years An administrator cannot directly access routers in other domains to isolate the problem The available options today are: –mtrace (bit like traceroute, useful tool, not supported by all routers) –Looking glasses There are several in use, but does not provide access to all routers and have different interfaces –Email is perhaps the most popular option Mail admins about possible issues, but hard to know in which domain the problem is as well

5. Connect. Communicate. Collaborate Interdomain multicast management tools There are some tools already available Active testing using dedicated groups –Multicast beacons, ssmping etc Several passive tools –MRM (Multicast Reachability Monitor) Passive and active. Can check whether an MRM node receives –mtrace Kind of traceroute for checking an active group –Mantra Periodic collection of multicast routing information from cooperating routers. Mainly provides historic data/statistics

6. Connect. Communicate. Collaborate Intradomain multicast management tools Several tools available In addition to the interdomain tools, there are some tools using SNMP to collect information from routers –Examples are mmon and MRMON These tools can provide information on current status, aid in diagnosing and isolating problems etc mcview is an attempt at providing some of the same functionality for interdomain multicast –They key issue is to do this without requiring SNMP across domains and only provide sufficient high level information

7. Connect. Communicate. Collaborate mcview overview Java based application, uses SNMP to gather status from routers Usually only the network administrators in a domain can use SNMP with the domain’s routers –To solve this, mcview can use agents Each domain should ideally run an agent –The agent talks SNMP to the local routers and aggregates and presents only the information needed for the mcview application No difference to the user if direct or via agent Data from multiple sources merged Will use PerfSONAR architecture for communication with agents, location service and AAA (only partial support right now)

8. Connect. Communicate. Collaborate mcview architecture Connect. Communicate. Collaborate router Agent mcview Agent snmp http

9. Connect. Communicate. Collaborate More on mcview Currently mcview can allow administrators and possibly end-users to get a view of multicast distribution trees and some other status Plan to add some automatic diagnostics that can highlight possible problems Typically used by administrators or end-users when experiencing problems Plan to do authorisation and differentiate between users and administrators, or between domains

10. Connect. Communicate. Collaborate mcview display of the IPv4 SAP group in UNINETT Connect. Communicate. Collaborate

11. Further information/download You can fetch the tool from http://software.uninett.no/mcview/ Please contact me if you have questions or feedback I would be quite happy for any feedback on functionality to add, user interface etc I can be reached at venaas@uninett.no