TP-LINK Smart Switches anyone?
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It all depends on how the manufacturer implements (maybe "presents" is better suited here) the 802.1q standard.
PVID (Port VLAN ID) is a default VLAN id assigned to frames arriving on the port.
In case of a 'trunk', it marks outgoing frames with the appropriate ID (vlan ID) from which vlan it originates on the switch.
For incoming frames, it is the same behavior: the vlan ID -gets stripped but- dictates on which vlan the frame is put (which broadcast domain it shares)Yet, a trunk always continues to support untagged frames as well. To my knowledge, untagged frames don't get dropped, but are placed on the switch'es 'native' vlan. And this is (among others) a reason why one should avoid the default vlan 1 as native vlan.
Hope this makes sense…
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yop, that makes sense… but one never knows, if tp-link is doing this with the easy smart switches like theory -- if one never wiresharked and checked. i guess...
but for now i found the theory for this strange pvid well explained... thanks...ozett
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a last post, because i found another default VLAN no 1 on openwrt.
if you change there the untagged to tagged value of an connected lan-port, traffic would go in the easy-smart switch default vlan.
to prevent this, one has to undertake some more steps. as mentioned before unter 'throwaway' vlan. first create a weired nr vlan for discarding all traffic on all used easy-smart-swiches, set all ports untagged to this pvid. than create and only allow vlan-numbers you want to allow. (take care with vmware vswitch, it uses 4095 as vlan-no. for all traffic…) on desired ports...
it took me some days of testing and understanding...
but thanks again for all explantions in this thread here.
ozett
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Merci de l'info.trop bien etui samsung galaxy tab housse samsung galaxy tab 4
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It all depends on how the manufacturer implements (maybe "presents" is better suited here) the 802.1q standard.
PVID (Port VLAN ID) is a default VLAN id assigned to frames arriving on the port.
In case of a 'trunk', it marks outgoing frames with the appropriate ID (vlan ID) from which vlan it originates on the switch.
For incoming frames, it is the same behavior: the vlan ID -gets stripped but- dictates on which vlan the frame is put (which broadcast domain it shares)Yet, a trunk always continues to support untagged frames as well. To my knowledge, untagged frames don't get dropped, but are placed on the switch'es 'native' vlan. And this is (among others) a reason why one should avoid the default vlan 1 as native vlan.
Hope this makes sense…
That seems like non-intuitive way to design a switch. My HP just lets me not assign a default VLAN. If no VLAN is assigned and an untagged frame comes in, it just blackholes it. poof. As I would naturally expect. My switch has no notion of a "default/native" VLAN. My desktop's port has a PVID of "none". It has access to all VLANS via tags, but there is no untagged VLAN.
At least in my case, the term "Trunk" is used to indicate if LACP is being used. VLAN wise, all ports are capable of being trucks if you tag all of the VLANs to a port.
Having an automatic "native" VLAN for untagged traffic sounds like a security nightmare.
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Keep in mind though that the price tag of these switches is very low compared to any HP or other corporate-ready switch series. They're intented for SOHO applications, thus the effort put into developing their software is scaled accordingly.
There are higher-class TP-Link models (L2 and L3), which can be configured almost as easily as an HP.
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That seems like non-intuitive way to design a switch. My HP just lets me not assign a default VLAN. If no VLAN is assigned and an untagged frame comes in, it just blackholes it. poof. As I would naturally expect. My switch has no notion of a "default/native" VLAN. My desktop's port has a PVID of "none". It has access to all VLANS via tags, but there is no untagged VLAN.
At least in my case, the term "Trunk" is used to indicate if LACP is being used. VLAN wise, all ports are capable of being trucks if you tag all of the VLANs to a port.
Having an automatic "native" VLAN for untagged traffic sounds like a security nightmare.
Well, newer sw implementations give more possibilities, also concerning the native vlan thing.
Google is your friend in this, just search for "native vlan", it is explained in so many ways there is really no point in repeating that here.
In most books I read, trunk = vlan trunk or dot1q trunk. (http://en.wikipedia.org/wiki/IEEE_802.1Q)
What you refer to, LACP (link aggregation), is called Etherchanneling aka 802.3ad. (http://en.wikipedia.org/wiki/EtherChannel)Though some vendors take different approaches in the terminology, so depending on your real-life experience you might be used to other 'slang' than me….
Now this was a total give-away on how I'm biased ::) (brainwashed)
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That seems like non-intuitive way to design a switch. My HP just lets me not assign a default VLAN. If no VLAN is assigned and an untagged frame comes in, it just blackholes it. poof. As I would naturally expect. My switch has no notion of a "default/native" VLAN. My desktop's port has a PVID of "none". It has access to all VLANS via tags, but there is no untagged VLAN.
At least in my case, the term "Trunk" is used to indicate if LACP is being used. VLAN wise, all ports are capable of being trucks if you tag all of the VLANs to a port.
Having an automatic "native" VLAN for untagged traffic sounds like a security nightmare.
Well, newer sw implementations give more possibilities, also concerning the native vlan thing.
Google is your friend in this, just search for "native vlan", it is explained in so many ways there is really no point in repeating that here.
In most books I read, trunk = vlan trunk or dot1q trunk. (http://en.wikipedia.org/wiki/IEEE_802.1Q)
What you refer to, LACP (link aggregation), is called Etherchanneling aka 802.3ad. (http://en.wikipedia.org/wiki/EtherChannel)Though some vendors take different approaches in the terminology, so depending on your real-life experience you might be used to other 'slang' than me….
Now this was a total give-away on how I'm biased ::) (brainwashed)
I learned a bit about terms today. "Trunk" seems to have not official definition besides the old usage for an "uplink" port, enabling 803.1Q(Multiple VLAN Registration Protocol) enables "Native VLAN" for many switches, Wiki says that "trunking" is "Link aggregation", but mentions "Cisco use the term Ethernet trunking to mean carrying multiple VLANs through a single network link through the use of a trunking protocol". Kind of funny, because Cisco uses the phrase "trunking protocol", but when you look at 803.1Q, the term "trunking" doesn't even show up expect in reference to Cisco's term.
Even though not official, "trunking" seems to make good sense when talking about VLANs since there are few other things useful for it to mean.
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Link aggregation is really more like "inverse multiplexing." Trunking where VLAN tags are concerned is more like TDM multiplexing, or "Trunk" lines, to go back to telco terminology.
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One important thing to bare in mind here is that all of the various interfaces and terminology you see on various switches are the result of the manufacturer (or software team) trying to make it easier to use the 802.1Q standard. For example in the low end TP-Link switches discussed here there are three VLAN 'modes' but the first two, MTU VLAN and port based VLANs are just subsets of the third designed to make it easier to implement common setups. It's particularly confusing since MTU is used here to mean something completely different to its common usage. ::)
Also I agree most vendors could learn from HPs relatively logical interface even for low-end stuff. :)
Steve
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I can't see any situation where that sort of asymmetric tagging/untagging would be anything but bad. Am I missing something?
In real-world setups probably not.
We have some installs of IP-TV systems where exactly this is needed. The vendor (justaddpower) uses a really tricky setup of vlans and subnets which took me about a week of e-mail ping-pong with the support to fully understand.
They prefer using Cisco SG300/500 in L3 mode and have transmitters/receivers sitting on overlapping subnets. Receivers have two untagged VLANs on their port. The one without the PVID is used for "listening" to the IP-TV stream only while the other is used for communication (very basically speaking).
The transmitter has the PVID on the "other" VLAN where it dumps the stream into and receives communications from the receives on the VLAN without the PVID.
Each stream resides in its own VLAN.
They achieve blazingly fast switching times between streams with this kind of setup by simply assigning another VLAN to the receiver's port.
To change a receiver's channel/stream I reconfigure the switch port to another (non-PVID) VLAN (via Telnet/CLI from a Crestron control processor…).
Granted, this is a very specific setup and uncommon in other installs. But it exists. -
The two "uplink" ports on mine are fiber only and are not any faster or anything but they can support a much longer distance of "cable". I'm not using them but I suppose if I had several buildings separated by 100m it would be handy.
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I have one of those, a TL-SL2428.
The problem I have is that every few days (7 to 21) the switch lost the remote web administration so I cannot login.
Any ones has come around this issue?
I have to say the switch is connected to 21 computers and 19 of them change ip from 3 to 5 times a week.The switch and the computers has all internet address, no local ones. No vlans, etc.
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I've got many of the Smart TP-Links (dozens) out there, all of them perform very well, no problems with management interface. One of them in my home has 72 day - 21 hour - 58 min uptime right now, and I've just read out this from the web interface.
Did you try to update the firmware to the latest version?
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I have no issues with TP-Link. I have a couple of their products and they work fine. I still prefer my switches though.
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Yes robi it has the latest firmware.
I think the problem may be to switch that lot of ips every week.
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Can you login via Telnet/CLI when the Web interface is gone?
Have a look at the CLI Guide to see which commands are available to check status etc. -
hello jahonix. There is no way to login to the swtich, web, ssh, telnet. I need to request remote hands to the datacenter to hard reset the switch and them yes, I can login. Thnx.
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You can also install a remote reset device to attach to your equipment.
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It may be that the specific switch is faulty. If it's still under warranty, try to RMA it.
