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Connecting two PowerConnect 2848 switches
I am having problems getting two 2848 switches to talk. If the switches are in close proximity (inches) and using Cat5e cable then all is OK. If I place one of the switches farther away (> 50m) through existing Cat5 cabling then there are no link lights, etc.. However, if I run the switches into the switch portion of a Netgear home router then communication is as expected. It is as though the Netgear is normalizing or amplifying signals between the 2848 switches. I have reset the 2848 switches to unmanaged mode with similar behavior. Is this an artifact of STP, incompatible wiring, improper autonegotiation, bandwidth limits? Thanks in advance for your insight.
Anonymous
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April 27th, 2012 06:00
Remember "The specifications for 10BASE-T networking specify a 100 metre length between active devices.:emotion-29: This allows for 90 metres of fixed cabling, two connectors and two patch leads of 5 metres, one at each end." So if you are using cables longer than 50m, you may be getting close this. Have we tried this 50m cable with other devices? To ensure the cable itself is functional. What happens when we try a cable shorter 50m but longer than a few inches? Do all ports act this way, or only certain ports?
Thanks.
rycm
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April 27th, 2012 16:00
The fix was to restrict the bandwidth of port(s) connecting the two switches to 100 Mb. The long in-wall cables were in fact split into two sockets at each end - each socket containing two twisted pairs. This is entirely satisfactory for 100baseT. On the other hand 1000baseT utilizes four twisted pairs and the speed negotiation begins at 1000. Since there is an incomplete signal the link light is off and, likely, no further speeds are attempted. Subsequently a LAG was created but that too needed to be throttled back to 100baseT to make it work.
Anonymous
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April 30th, 2012 06:00
Glad to hear you got this resolved, andthank you for sharing what you found the fix to be, I am sure others that run into this issue will appreciate the information.
Thanks