Re: [c-nsp] Bandwidth Statement - Tunnel Interface
Hi, On Fri, Dec 4, 2009 at 2:55 AM, sky vader aptg...@gmail.com wrote: So what does tunnel bandwidth transmit / receive statement under tunnel interface do? For example: I guess it could be useful if the underlying physical transmission was asymmetric in nature, e.g. ADSL. Ultimately, though, the bandwidth transmit/receive statements achieve the same things as just bandwidth. Jay covered this well. cheers, Dale ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] Bandwidth Statement - Tunnel Interface
see in-line: Jay Hennigan wrote: sky vader wrote: Hi, Just curious, since the default bandwidth for tunnel interface is 9k (cisco platform), does that mean the maximum bandwidth I can have is 9k? No. - So what does tunnel bandwidth transmit / receive statement under tunnel interface do? For example: interface tunnel0 bandwidth 4 ip address 192.169.0.1 255.255.255.252 tunnel destination x.x.x.x tunnel bandwidth transmit 4 tunnel bandwidth receive 4 thanks, sky What's the purpose of setting bandwidth statement on a tunnel interface? Does that mean I get bandwidth that is set or what the router will report via snmp? Three things come to mind, there are likely other subtle ones... 1. Dynamic routing protocols use the interface bandwidth for path selection. Manually specifying the bandwidth to something sane for the physical path over which the tunnel rides may be needed for proper route selection. 2. MRTG and similar tools will use the configured bandwidth as the default maximum for graphing and analysis purposes. Leaving it at 9K is likely to result in graphs topped at that value. SNMP of the actual traffic counts will be accurate, but configuration tools of graphing software will get the configured bandwidth on setup and may behave as if this is the physical limit. 3. QoS and traffic shaping applied to the interface will use the configured bandwidth for percentage calculations and the like. This will almost certainly cause results that aren't what you expect unless the tunnel is running over a dialup link. If you are doing none of these, then the configured bandwidth statement really doesn't affect anything in terms of operation that I've noticed. -- Jay Hennigan - CCIE #7880 - Network Engineering - j...@impulse.net Impulse Internet Service - http://www.impulse.net/ Your local telephone and internet company - 805 884-6323 - WB6RDV ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
[c-nsp] Bandwidth Statement - Tunnel Interface
Hi, Just curious, since the default bandwidth for tunnel interface is 9k (cisco platform), does that mean the maximum bandwidth I can have is 9k? What's the purpose of setting bandwidth statement on a tunnel interface? Does that mean I get bandwidth that is set or what the router will report via snmp? Insight will be appreciated. regards, sky ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] Bandwidth Statement - Tunnel Interface
sky vader wrote: Hi, Just curious, since the default bandwidth for tunnel interface is 9k (cisco platform), does that mean the maximum bandwidth I can have is 9k? No. What's the purpose of setting bandwidth statement on a tunnel interface? Does that mean I get bandwidth that is set or what the router will report via snmp? Three things come to mind, there are likely other subtle ones... 1. Dynamic routing protocols use the interface bandwidth for path selection. Manually specifying the bandwidth to something sane for the physical path over which the tunnel rides may be needed for proper route selection. 2. MRTG and similar tools will use the configured bandwidth as the default maximum for graphing and analysis purposes. Leaving it at 9K is likely to result in graphs topped at that value. SNMP of the actual traffic counts will be accurate, but configuration tools of graphing software will get the configured bandwidth on setup and may behave as if this is the physical limit. 3. QoS and traffic shaping applied to the interface will use the configured bandwidth for percentage calculations and the like. This will almost certainly cause results that aren't what you expect unless the tunnel is running over a dialup link. If you are doing none of these, then the configured bandwidth statement really doesn't affect anything in terms of operation that I've noticed. -- Jay Hennigan - CCIE #7880 - Network Engineering - j...@impulse.net Impulse Internet Service - http://www.impulse.net/ Your local telephone and internet company - 805 884-6323 - WB6RDV ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
