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Re: [afnog] Oposite of VPN ?



Great!
I will take care of all theses advices!
I learn enough to go on with google, 
tanks again, Mark.

--
Mohamadi ZONGO

Selon Mark Tinka <mtinka at africaonline.co.ug>:

> 
> Well, looking at D-Link's website, I assume you are talking about the
> DES-3624i 'managed' switch. You are in luck, because you can do inter-VLAN
> switching with this switch.
> 
> Just remember that because you are going to use Cisco routers with non-Cisco
> switches, you will want to maintain the use of standards-based protocols. For
> inter-VLAN switching, you will go for IEEE's 802.1Q VLAN protocol. Also, to
> prevent recurring paths [switching loops] at Layer 2, use IEEE's 802.1D STP,
> since switches/bridges can't decrement TTLs like routers can.
> 
> However, looking at your routers, I don't seem to see any that supports a
> FastEthernet configuration by default. IIRC, VLAN trunking requires a port to
> operate at 100Mbps. I know ISL can run on 10Mbps trunk ports, but the limited
> bandwidth and other considerations make it rather impractical. Just to be
> safe, you might want to upgrade to FastEthernet ports.
> 
> The actual implementation of these protocols and features is slightly
> different with each vendor, although the end result is achieved. For this,
> you may want to consult the product manuals, or download any PDFs, if
> available, from your vendor's website.
> 
> Once your VLANs are created, you can multiplex all of them on a trunk port to
> which your router is connected. Of course, you will need to configure
> FastEthernet subinterfaces to represent each VLAN that needs to cross the
> trunk port.
> 
> Also, a very important note to remember, VLAN trunking is usually available,
> at a minimum, on the IP PLUS featureset of Cisco's IOS images. I haven't yet
> come across one of the basic IP image that support this. IP PLUS images will
> usually require more flash and more memory. A quick look says IP PLUS for
> 12.2 on 2611 requires 16MB Flash and 64MB RAM. Of course, lower major IOS
> version in the same category may require less resources. You will have to do
> some digging.
> 
> If you can't upgrade memory and flash at the same time, you could run the IOS
> image of a TFTP server. The only problem with this is that FastEthernet
> subinterfaces are logical/software interfaces, and are not seen by the router
> until the IOS has successfully and fully loaded. This means that booting off
> a TFTP will only work if you have IP processing enabled on the major
> interface as well as the FastEthernet subinterfaces, which could be a bit
> crude :-), since the Bootstrap will only load the driver for the major
> interface to allow a TFTP download, and not the FastEthernet subinterfaces
> themselves.
> 
> If you do decide to boot off TFTP server, remember the STP will need to
> converge each port through various transitions to ensure no loop occurs once
> the port is in forwarding mode. During this time, communications between your
> router and the TFTP server will timeout. To solve this, you will need to
> disable STP on the specific port you have connected your router to. This will
> allow the port to transition to forwarding state immediately.
> 
> Okay, let me stop here... I could go on and on :-) {/sbin/halt}
> 
> Regards,
> 
> Mark Tinka - CCNP
> Network Engineer, Africa Online Uganda
> 
> 
> 


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