A Tunnel interface is nothing more than just a process of putting another layer of headers onto an existing datagram to protect or hide its internal headers. There is no physical interface related to the operation of a Tunnel interface. Once a tunneled packet is created, it is forwarded through some other physical interface on the device that performs the tunneling.
There are two possible bottlenecks that ultimately define the bandwidth as seen by a Tunnel interface. The first bottleneck is the CPU of the router if the tunneling operations are performed in the operating system and not in specialized hardware. Too many packets to be tunneled can easily overwhelm the CPU and its capabilities. The second bottleneck is the physical inteface itself that will be used to send out the tunneled packet.
On Catalyst 3xxx switches, there is no hardware support for tunneling operations, meaning the GRE tunneling encapsulation and decapsulation is performed in software and must be executed on the CPU. While there is no official benchmark as far as I know, I estimate that with the CPU in a Cat3750G, the throughput of a GRE tunnel is, at most, in orders of Mbps or tens of Mbps in ideal conditions. I do not think anyone will be willing to guarantee this figure, as these devices are not really intended to terminate GRE tunnels.
Apart from that, however, you do not really care about the bandwidth command setting on Tunnel interfaces, as that command has no influence on the real throughput of this interface - it just influences routing protocols like OSPF and EIGRP in their best path selection, and it may impact QoS mechanisms if applied to the Tunnel interface. However, if none of this is of a concern, simply configure the bandwidth command on a Tunnel interface to, say, 1000 (meaning 1Mbps) and you should be fine.
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.