| Author |
A basic query reg interconnecting switches
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| ss2001 2003-04-28, 5:17 am |
| Hello all
I wud like to know the difference bet casading switches & stacking switches.What exactly is the difference bet the two?Also pl let me know the difference bet ring topology connection of switches & star topology
Thanx in advance
ss | |
| wirelessboy 2003-04-28, 8:58 pm |
| thanks in advance guys
i always wanted to ask someone this question.
diff between stacking and cascading
thanks ss | |
| darthfeces 2003-04-28, 11:31 pm |
| depends on if your using a x-over or a trunk to interconnect.
stacking usually implies a switch cluster
which means your using trunk between switches.
daisy-chaining or cascading implies you are using a x-over to carry over 1 vlan between switches.
to complicate things you could x-over between two 100/mb switchports and trunk them.
i'ts still flat either way. | |
| darthfeces 2003-04-28, 11:40 pm |
| now that i think about this the physical cable is irrelevant. it's just how you handle the link ... either static using 1 vlan or trunk to propagate all configured vlans. | |
| wirelessboy 2003-04-29, 9:26 pm |
| so cascading means just interconnecting two or more switches, to get physical connectivity.
stacking is something more intelligent, like trunking and using different vlans, like using vtp right?
thanks | |
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| I've always seend the two terms used interchangebly.
Cisco sell Stacker modules, 3Com sell cascade modules.
If you look in the Ggastack datasheet they use the term cascade to infer that multiple switches are in a connected in a daisy chain topology, they then refer to a star formation also. They don't mention trunking.
I just think theyre marketing terms.
http://makeashorterlink.com/?A30821464 | |
| darthfeces 2003-04-30, 9:03 am |
| yeah, yuck .....
i was just trying to explain the differnce | |
| SureshHomepage 2003-05-02, 8:58 pm |
| Hi darthfeces!
I do not agree to your point that x-over carries a single VLAN.
The GBIC stack ports as wells as any of the switch ports can be made as a trunk to carry multiple VLANs. On the other hand as you said they can also be configured as access links to carry one single VLAN.
The point here is if you connect them as stack it would mean you are effectively using the GBIC stack ports of the switches which gives a 1Gig uplink speed and if you make the last switch connected back to the first switch you now effectively increased this backplane capacity to 2G. This is called stacking/daisy-chaining.
The disadvantage here is that they need to be in the same or adjacent wiring closet there is a restriction can not run the interconnecting GBIC stack cables more than 1-2mts. This is a special cable shipped along with a GBIC while ordering.
The other way is just using any of the switch ports that are normally used for connecting the PCs that are now used for inter-connecting the switches. This way you would get a 100Meg uplink. The variation to this is if you use an Etherchannel to bundle the individual ports to increase the uplink capacity. Remember if you do not use Etherchannel all the parallel links would be blocked except one single link due to Spanning tree protocol.
Back to the point, this cross-over cable cascading increase collisions in case if they are used as access link. Because you are sharing one single collision domain (each sw port is a collision domain) with over 24/48 ports belongs to another cascaded switch. If its made as a trunk link no worries at all but restrictions apply on the uplink speed.
The advantage of using x-over is that the cascaded switch can be anywhere reachable by Ethernet technology could be sitting on the next floor or on any other building provided fiber (using media converters) is used between them.
Hope this would help…! | |
| darthfeces 2003-05-05, 12:59 pm |
| i was not that clear in my explanation ..
sorry ....
i meant you couls either x-over 1 vlan on a static port OR trunk it . | |
| limsam 2003-05-06, 9:05 pm |
| I am also confused!
I have seen 3com also sell 'stackable switches'. What they mean by stacking is that you connect 2 or more switches with a 'matrix cable' so that these bunch os switches act as a single unit.
3com uses the word 'cascading' when you connect switches with a X-over or straight-thru cable to extend the LAN (or the smae vLAN.)
Do you see any similarity with Cisco?
Or is it another marketing trick? | |
| SureshHomepage 2003-05-09, 6:07 pm |
| I am predominantly using Cisco switches in all the installations and never had a chance to work with 3COM in recent days. The last one I worked on 3COM was about 5 years ago if I remember correctly it was the 'switch 3000' and 'switch 1000' models. Have anyone here got the answer for his question? |
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