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I think if you set the local site to “on”, also the remote site must support it (on or desired), otherwise it will not work. But I’m not 100% sure, so lab-it-up ) According to the documentation, there is “no” difference between on and desirable in the receive direction. Have a look at the Usage Guidlines which I’ve pasted below: ———————— Usage Guidelines
When software flow control is set, the default stop and start characters are Ctrl-S and Ctrl-Q (XOFF and XON). You can change them using the stop-character and start-character commands.
If a remote Telnet device requires software flow control, the remote system should not be able to turn it off. Using the lock option makes it possible to refuse “dangerous” Telnet negotiations if they are inappropriate.
Catalyst 6500 Series Switches and Cisco 7600 Series Routers
The send and desired keywords are supported on Gigabit Ethernet ports only.
Pause frames are special packets that signal a source to stop sending frames for a specific period of time because the buffers are full.
Gigabit Ethernet ports on the Catalyst 6500 series switches and on the Cisco 7600 series routers use flow control to inhibit the transmission of packets to the port for a period of time; other Ethernet ports use flow control to respond to flow-control requests.
If a Gigabit Ethernet port receive buffer becomes full, the port transmits a “pause” packet that tells remote ports to delay sending more packets for a specified period of time. All Ethernet ports (1000 Mbps, 100 Mbps, and 10 Mbps) can receive and act upon “pause” packets from other devices.
You can configure non-Gigabit Ethernet ports to ignore received pause frames (disable) or to react to them (enable).
When used with receive, the on and desired keywords have the same result.
All the Gigabit Ethernet ports on the Catalyst 6500 series switches and the Cisco 7600 series routers can receive and process pause frames from remote devices.
To obtain predictable results, follow these guidelines:
Use send on only when remote ports are set to receive on or receive desired.
Use send off only when remote ports are set to receive off or receive desired.
Use receive on only when remote ports are set to send on or send desired.
Use send off only when remote ports are set to receive off or receive desired.
—–Urspr|ngliche Nachricht—– Von: nobody@groupstudy.com [mailto:nobody@groupstudy.com] Im Auftrag von Igor Manassypov Gesendet: Dienstag, 19. August 2008 00:09 An: Roger RPF; ‘Igor Manassypov’; ‘Cisco certification’ Betreff: Re: AW: switch flowcontrol feature
Hey Roger,
I saw those briefs on cisco doc cd, however they are not explaining much. For example, if you ‘flowcontrol receive on’ on a port which the other side does not support - is the port going to function at all? And whats the point of having the ‘on’ if there is ‘desirable’?
Roger RPF wrote: flowcontrol receive on: Enables a local port to receive and process pause frames from remote ports.
flowcontrol receive desired: Obtains predictable results regardless of whether a remote port is set to on, off, or desired.
regards
Roger
—–Urspr|ngliche Nachricht—– Von: nobody@groupstudy.com [mailto:nobody@groupstudy.com] Im Auftrag von Igor Manassypov Gesendet: Montag, 18. August 2008 20:17 An: Cisco certification Betreff: switch flowcontrol feature
Anyone knows whats the difference between ‘flowcontrol receive on’ vs ‘flowcontrol receive desired’?
Igor M., M.Eng, P.Eng Network Architect
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