Cisco Switching/Routing :: Random Port Disconnect 3750

Apr 24, 2012

We have computers that are connected to a switch stack of 3 - 3750 switches.  Randomly, we experience pcs that fail to communicate on the network. At first thought I figured the port went into err-disabled state, however the port shows up fine on the switch and moving the pc to another port on the same switch in the stack fails to fix the problem.  To add to the confusion, if I immediately connect a different machine into the problematic port the newly connected machine has no issue and operates normally.  Connecting back the first machine still results in no connectivity. 
The only way to gain back network connectivity is to move the pc to a different switch in the stack.  shut/no shut doesn't work.The IOS the stack is running is 12.2 and the switch ports are configured using cisco port macros.
here is how all the ports are configured.
switchport mode access
switchport port-security
switchport port-security aging time 2
switchport port-security violation restrict
switchport port-security aging type inactivity
macro description cisco-desktop
spanning-tree portfast
spanning-tree bpduguard enable

View 5 Replies


Cisco Switching/Routing :: Replacing 3750 24 Port With 3750 48 Port?

May 21, 2012

We have a stack of switches that is at the max number of members allowed in the stack. Problem is we are running out of port density and need to add more ports. So instead of adding a whole new stack I would rather replace 2 of the 24-port swicthes with 48-port switches.
If the two 24-port swicthes we are removing are stack members and neither of them are the stack master, I should be able to replace the 24-port switches with the 48-port switches without bringing the master offline? If the new 48-port switches are running the same IOS version as the current 24-port swicthes, they should add themselves to the stack?Would I have to tell the new 48-port swicthes what switch numbers they are replacing in order for them to be added to the stack since we are at the max number of members?Also since the 48-port swicthes are replacing 24-port switches will the master give the 48-port switches the configuration for only the 24-ports?

View 11 Replies View Related

Random Disconnect But Still Says Connected?

Aug 31, 2011

Ill get on my laptop and it will connect for 45min-hour and then it will disconnectEverything says connected on the laptop and the router and modem are connected and working. I have tried restarting my router and modem and even clean installed windows and reinstalled drivers. Nothing seems to work. Im posting from my old laptop and it seems to happen on this computer as well. This has never happened before.

View 9 Replies View Related

Internet Slowdown And Random Disconnect

May 27, 2011

Recently I bought a new PC to replace an old laptop that I use in my bedroom. However, initially I couldn't pick up my downstairs router signal. So, I bought a new wireless network card and STILL didn't pick up any signal. I then purchased a Netgear WN200RPT and everything seemed to be ok while using that to repeat the signal up into my bedroom. Then, suddenly, it all stopped working. The WN200RPT would, although showing a full internet connection with no yellow ! or red x's, it would never ever load webpages. So, I removed it and put it back in its box. Then, for some unknown reason after a Windows 7 reinstall, my network card started picking up the signal from my home router and had a good speed and signal. This worked fine for a month or two before it started playing up again. It would randomly slow down and stop loading webpages, or completely lose the signal and show a red x, stating that no signals could be found. The strange thing is, all the other PCs in my house connect wirelessly fine, and so did the laptop that was in the same room as this PC. After a system restore, the internet started working again. Then it stopped. Another restore later, it works. Now it's intermittent again.

View 3 Replies View Related

Internet Random Disconnect And Reconnect

May 15, 2011

When doing anything on my PC, gaming, browsing, whatever, I will have random disconnects for a few seconds and it will reconnect. I don't get the "your network cable has been unplugged" message, it just stops working for a second or two and starts working again. This has been happening for a few months after a fresh install of windows xp and I haven't really tried to fix it.Every other computer in the house is fine except this one, it can't be the modem because a new one was installed a few days ago and its the same problem. The router was reset within the last week as well. I think the problem is with this computer alone but I don't know where to look.  The problem didn't happen for a few days after I put a new network card in, but soon after it continued happening. I also have tried a few different CAT5 cables, even the XBOX one but nothing resolved the issue.

View 4 Replies View Related

Random Instant Disconnect / Reconnects While Uploading

Dec 3, 2011

Basically i'm an employee of a Pro-Gaming team, and as a Job I stream games live, as well as upload game videos to youtube. I've been encountering a problem for a month or so now and had little success of fixing it, which is costing me quite a lot of money and viewers! Basically, I use a program called Xsplit to stream to a website called (no-one else i've spoken to has the problem I have). I will randomly disconnect/reconnect instantaneously which puts my stream down for 5-10 seconds at a time, then goes back up again. Ultimately the viewing experience is ruined by this and I am on the verge of being replaced!The problem can occur either once a week or once every minute.. it just does it whenever it wants. I have 200mb/10mb internet so my upload should in theory not be an issue.

Things I have tried and done so far:
- Replaced the Ethernet Cables.
- Replaced the Routers.
- Bought a Network Card to try as opposed to my Motherboard port.
- Reformatted my computer and installed a different version of Windows 7 multiple times.
- Spoken to and Xsplit about their programs as well as used multiple versions of the Xsplit client.
- Spoken to my ISP who say everything is fine.

View 7 Replies View Related

Cisco VPN :: 1841 / 1801 - Random L2L IPSEC VPN Disconnect

Aug 9, 2011

Network Setup

2 Site to Site VPN tunnels has been established, it is a hub and spoke topology. The hub is ASA5520 and the 2 spoke are a 1841 and 1801 router. The tunnel is able to pass traffic, it's a full tunnel VPN.The tunnel randomly disconnect for no reason. When I check the logs I can see some errors :

%CRYPTO-4-RECVD_PKT_INV_SPI: decaps: rec'd IPSEC packet has invalid spi for destaddr=x.x.x.x, prot=50, spi=0x5F822579(1602364793), srcaddr=y.y.y.y
%CRYPTO-4-IKMP_NO_SA: IKE message from y.y.y.y has no SA and is not an initialization offer
The actual address have been replace by x.x.x.x and y.y.y.y. I frequently have to peform clear crypto isakmp on the spoke routers to revive the VPN tunnels. Is there a way the tunnel can be re-establish again without manual intervention?This keep happening on a random basis and I have living with it for years. I have looked at cisco website troubleshooting tips and but no luck in finding out how to resolve it.
Below is my config on one of the spoke router:
Cisco IOS Software, C180X Software (C180X-ADVIPSERVICESK9-M), Version 12.4(24)T3, RELEASE SOFTWARE (fc2)
crypto isakmp policy 10encr 3deshash md5authentication pre-sharegroup 2crypto isakmp key @@@@@@ address y.y.y.ycrypto isakmp invalid-spi-recoverycrypto isakmp keepalive 30 periodiccrypto isakmp nat keepalive 20!!crypto ipsec transform-set tset1 esp-3des esp-md5-hmaccrypto ipsec df-bit clear!crypto map ipsecvpn 10 ipsec-isakmp
set peer y.y.y.yset transform-set tset1match address vpn@spoke!archivelog config  hidekeys!!!!!interface FastEthernet0ip address x.x.x.x nat outsideip virtual-reassemblyduplex autospeed autocrypto map ipsecvpn!interface FastEthernet1!interface FastEthernet2!interface FastEthernet3!interface FastEthernet4!interface FastEthernet5!interface


View 4 Replies View Related

Cisco Switching/Routing :: 3750 Stack Port

May 19, 2013

I have a stack of 4 3750 Switches.
1. WS-C3750G-12S
2. WS-C3750G-12S
3. WS-C3750X-48P
4. WS-C3750X-48P
The stack cable connected to Switch 1 Port 1 and Switch 4 Port 2 will not come back online. The logs show that there was a Stack line change. I have replaced the 1 meter Stack cable from Switch 1 to Switch 4 three times and it still does not come back online. This is the part that is interesting.. I have disconnected Port 1 Switch 4 and connected it to Port 2 Switch 4 and then Switch 4 came back online. This made me think Port 2 on Switch 4 was working correctly. Then I disconnected Port 2 Switch 1 and connected it to Port 1 Switch 1 and then Switch 1 came back online.

View 1 Replies View Related

Cisco Switching/Routing :: Stack Port Down On 3750

Mar 11, 2013

have a cable i think is bad, is it possiable to switch the cable out without causing any downtime to the switch or connected devices?
HQ-1st-Flr-Stack#show switch stack-ports summary
Switch#/  Stack   Neighbor   Cable    Link   Link   Sync      #         In 
Port#     Port              Length    OK   Active   OK    Changes   Loopback
Status                                          To LinkOK   


View 15 Replies View Related

Cisco Switching/Routing :: 3750 - How To Enable SFP Port

Nov 7, 2011

I am trying to configure a 3750 48 port switch and having trouble with getting it to see the sfp. I just want to set up the router with a pretty basic set up since I am using it for a ping test between 2 buildings, via fiber. How I can enable the sfp port?

View 3 Replies View Related

Cisco Switching/Routing :: Destination Port Protocol Is Down In 3750

Jun 18, 2012

I have configured SPAN in cisco 3750 switch as below mentioned. but the destination port protocol is down.switch(config)#monitor session 1 source interface gigabitethernet1/0/1switch(config)#monitor session 1 destination interface gigabitethernet1/0/11 ingress vlan 1

View 8 Replies View Related

Cisco Switching/Routing :: VTP Traffic Not Seen On SPAN Port On 3750

Dec 12, 2011

Been dealing with a strange problem for several days now.  It started out with a problem that I thought was VTP related but ended up being something else.  I setup a span port on a 3750 that I am connected to that was mirroring the trunk connection coming into the switch.
Never saw an VTP traffic come across the connection but doing a sh vtp status indicated the traffic was arriving and getting processed.  When I found some debug commands (debug sw-lan vtp), I was also able to see the packets go between switches.  Seeing this issue concerns me that there is other traffic that isnt showing up during a span session.
I know that doing a span on a switch, especially using a trunk port as a source, isnt a good idea.  Since I didnt have a TAP at time, this was my only choice.  I have since borrowed a NetOptics TP-CU3 tap from a good friend and was able to confirm the VTP traffic was going across the trunk connection between switches.
All of my 3750's are running 12.2.55.SE.

View 8 Replies View Related

Cisco Switching/Routing :: 3750 As A Port Channel Bridge?

Dec 7, 2011

I have 3750 core/distribution switches with routing enabled in two offices connected with copper link and L3 port channel interfaces. NewOffice#2 has moved about 5 miles farther away from office#1 and I have to deploy new core/distribution switch connect it to old core#2 via F.O and move all access switches with it. Old core will stay in old #2 offices as a bridge between office#1 and new office#2 Office#1core<->copper (Ethernet) <->oldoffice#2core<->f.o. <->new office#2core How I should configure port channels ports on oldoffice#2 core to act as bridge between office#1 core/dist and newoffice#2 core/dist without changing anything else (ip, etc) on whole network

View 1 Replies View Related

Cisco Switching/Routing :: 3750 No MAC Address On Switch Port

Apr 15, 2012

There 's a Cisco IP phone that sits between a PC and the switch port. On the switch port, no MAC address is learned. However, the switch is able to detect the IP phone and deliver power to it: [code] Switch is Catalyst 3750 with IOS version  12.2(58)SE1.

View 1 Replies View Related

Cisco Switching/Routing :: 3750 Port-security Will Not Clear

Jun 5, 2012

We have several 3750 stacks across our campus that we are unable to completely clear port security on. We have mac address stick set up on all access ports. When we clear the sticky address on the port, the mac address is removed from the running config like normal, but we keep getting port-security voilations. If port security is taken off the port completely, i.e. no switchport port-security, traffic still doesn't pass the port. Even clear port security across the stack doesn't work. If we try to reload the stack, only the master reboots, and the other switches in the stack lose switch capabilities.

View 1 Replies View Related

Cisco Switching/Routing :: 3750 Port Forwarding Inbound

Dec 15, 2011

I have a non-cisco router with a public WAN address. This is conencted to a 3750 switch internally. The switch is the default gateway for all VLANs, and the gateway router has static routes back to the 3750. The Router provides NAT, no NAT is done on the switch.My requirement is to port forward port 29 000 so that I can access a server on VLAN4 via this port.

So, I have: Router: Port 29000 map to (Switch VLAN4 address)
The question is, how do I route port 29000 from the 3750 to the server on ? what exactly I should add in order to port forward port 29000 incoming form my router, to my server on

View 17 Replies View Related

Cisco Switching/Routing :: How To Monitor 3750 Stacking Port In LMS

May 24, 2012

I would like to ask about 3750 stacking and some Cat6 stuff...
1) How do we monitor 3750 stacking port in LMS?
2) Let say if I stack 3 switches, middle switch should be Master. Uplink should be at Top and Bottom. Is best practice?
3) Can we mixed 3750G and 3750X and what is result internal BW - fallback to 32Gps?
4) is there any Qos difference between WS-X6816-10G-2T and WS-X6816-10G-2TXL?
5) is there any Qos difference between MSFC5 PFC4 and MSFC5 PFC4XL?
6) What is main difference between PFC4 and PFC4XL in Sup2T?
7) Pls share more about Central and Distributed Switching in Sup2T and which card support Distributed DFCXL?

View 3 Replies View Related

Cisco Switching/Routing :: 3750 Switch Stack-port Changes

Feb 7, 2011

I have a stack with a lot of stack-port changes, but on all the ports, how can I determine the faulty switch in the stack, cables are already verified. We did also a restart of the whole stack power off/on
running version
WS-C3750-48P       12.2(55)SE            C3750-IPBASEK9-M
This is the output after 6weeks
Switch#/  Stack   Neighbor   Cable    Link   Link   Sync      #         In  Port#     Port              Length    OK   Active   OK    Changes   Loopback          Status                                          To LinkOK          --------  ------  --------  --------  ----  ------  ----  ---------  --------  1/1     OK         4      1


View 7 Replies View Related

Cisco Switching/Routing :: SPAN Port Configuration On 3750?

May 23, 2012

I'm trying to configure a mirror port on a 3750. This configuration needs to replicate data from local ports, but I need that also act as a regular access port.
With the initial configuration, SPAN port, there is no problem, all the data of the configurated ports is replicating in the configurated port. On the port configurated as mirror there is a PC connected for audio recording. When the port is not operating as SPAN there is communications without problem over the LAN. But when I configure the port as SPAN, communication is interrupted.
Here is the actual configuration:
SWITCH1-PISO7#sh monitor session 1
Session 1
Type                   : Local Session


View 5 Replies View Related

Cisco Switching/Routing :: 3750 - How To Setup Port-channel

Jan 22, 2012

I set up a port-channel trunk between a acess switch 3750 ( int gi2/0/1 and gi2/0/2) and Core 6509( int gi7/11 and gi7/12).
On the both the 3750& 6509 I configured:
interface Port-channel15
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 100,103
switchport mode trunk
But the ports on the core g7/11 and g7/12 keep shutdown and when I do show interfaces port-channel 15, it show the interface is shutdown.

View 6 Replies View Related

Cisco Switching/Routing :: Min-Link Configuration On 3750-X Port-channel

Feb 27, 2013

I am building a new network and intended on using the min-link feature on my port-channels between a 3750-X series switch and Nexus 4k.

However reading further into this it seems this feature is only supported on higher end models. I cannot find any reference to the min-links feature in the 3750-X configuration guide. Is this an available feature?

The 3750-X model is WS-C3750X-24T-L running IOS 12.2(55)SE3 IP Services

My thoughts is that the is only an LACP supported feature so I may not see the command until I have entered an LACP specific command on the port-channel but unfortunately I do not have a 3750X to verify this on at present.

View 0 Replies View Related

Cisco Switching/Routing :: Config Port Forwarding In 3750 Switch

Nov 6, 2012

I have a 3750 catlyst switch in my network and it is like a distubation switch,And for the nating and dhcp nomadix is using as gateway in the same network. for one of my local PC i need to config the port forwarding in 3750 switch. How to config the port forwarding on 3750 switch,

View 3 Replies View Related

Cisco Switching/Routing :: 3750 - Setup A Switch Port For 2 Vlans

Nov 8, 2011

I'm trying to setup a port on a catalyst 3750 so it will pass traffic for 2 vlans. It connects to a (watchguard) firewall which I've configured with a primary IP (for vlan 27) and a secondary IP (for vlan 29).
However I can't seem to find the correct commands to enter on the cisco switch port (I've tried a variety).
FYI the current configuration is...
interface FastEthernet1/0/38
description ## Connection to WG vlan27 and vlan 29 ##
switchport trunk encapsulation dot1q


View 8 Replies View Related

Cisco Switching/Routing :: QoS 3750 Switch Port Trust Without Resetting

Oct 7, 2012

We have QoS configured throughout the company, but the standard config we have applied across the 3750 switches only includes the below: We have IP phones (not cisco) attached that are marking with EF, and the PC is an untrusted end device (so needs to be by default marked as zero).Is the above enough to trust VOIP DSCP EF without resetting it to DSCP 0, or do I also need to add a trust line (i.e.: mls qos trust dscp)?

View 2 Replies View Related

Cisco Switching/Routing :: Port Grouping On 3750 Like On Catalyst 4500?

Mar 27, 2013

On 45XX catalyst , bandwidth is allocated across six 8-port groups, providing 1 Gbps per  port group. Example  for the following line card : WS-X4448-GB-SFP

I want to know if there is the same mecanism on 3750X switches. I mean is bandwidth allocated across a group of ports like on 4500 catalyst ?

View 5 Replies View Related

Cisco Switching/Routing :: Auto Qos Dropping Port Channel In 3750?

May 13, 2012

We have a switch that, when configuring auto qos on and edge port facing video equipment, the upstream port channel drops. I was wondering if no auto qos would have to be configured on the member ports of the port channel prior to enabling auto qos on any other ports. 

View 2 Replies View Related

Cisco Switching/Routing :: Port Goes Into Error Disable State 3750

Jun 29, 2012

We have a number of 3750 stacks used as access layer switches connecting Siemens VOIP phones and then a PC that connects to the phone.
For example if I plug PC A to the phone that connects to port 13 I pick up an IP addressand all works as predicted now if I plug in PC A to any other VOIP phone that connect to another port on the same switch it goes in error disable state ITs like the switch is holding my PC mac address and locks it down with the port which in my case is Gi2/0/13.
interface GigabitEthernet2/0/13
switchport access vlan 726
switchport mode access


View 7 Replies View Related

Cisco Switching/Routing :: Rate Limit Trunk Port On 3750?

Oct 3, 2012

Is it possible to rate limit on a L2 trunk port on a 3750?
current port config and ios are as follows;
interface GigabitEthernet1/0/50
description ***  Connection to Fiber Link  ***
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,172
switchport mode trunk
i was wondering if the "srr-queue bandwidth limit 10" command would work to limit the output from this interface to be 10 % of the port bandwidth and then the same command could be done on the other side.

View 1 Replies View Related

Cisco Switching/Routing :: 3750 - How To Isolate Fiber Port Traffic

Jun 18, 2012

We would like to setup a link to our DR site that is separate from our main network traffic.  This link will be used by an EMC VNX SAN for replication traffic.  The SAN will be plugged into a fiber port on a 3750 switch and going out from the same switch (going in as multimode, going out as single mode) into a patch panel that runs over to the DR site (about a mile away).  At the DR site it will go from the fiber panel into another 3750 switch which ends up going back out of that switch into our DR SAN.
I'm wondering what the best way would be to configure the fiber ports to accomplish this.  I'm affraid that the replication traffic will find it's way over through another route and congest our main network unless configured appropriately.

View 4 Replies View Related

Cisco Switching/Routing :: How Many Port Channel Can Configured In Switch 3750 X

Apr 23, 2012

I would like to know how many port channel can i configured in the switch 3750 X ? and if there is a limitation by IOS ?

View 4 Replies View Related

Cisco Switching/Routing :: 2960 / 3750 - Port Disables Every 10 Minutes

Aug 15, 2012

I am experiencing the same problem described in this post {URL}. I have seen this happen on different networks, with different equipment attached. It happens on both 2960 and 3750 switches. Basically the connection drops, and we see in the web interface "Port is Disabled". This appears to happen every 10 minutes.
On the CLI, the status shows as connected.
Port Name      Status       V lan       Duplex  Speed Type
Fa0/38             connected     1          a-full  a-100 10/100BaseTX
I have ran cable diagnostics while the drop out is occurring.
Interface Speed Local pair Pair length        Remote pair Pair status
--------- ----- ---------- ----------------- ----------- -------------------
Fa0/38    100M  Pair A     28   +/- 15 meters Pair B      Normal
During the outage, I see the duplex fluctuate between full and half. The outage occurs for approx 90 seconds. If I fix the duplex and speed at both ends, the outage reduces to around 30 seconds. If I apply spanning-tree port fast the outage reduces further to around 10 seconds. Before I change any configuration on the port, the logs show the interface going down
Aug 16 13:06:51.875: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/38, changed state to down
Aug 16 13:06:52.874: %LINK-3-UPDOWN: Interface FastEthernet0/38, changed state to down
However, once I apply the configuration nothing is logged. However we can still see the connection is disappearing for around 10 seconds. I suspect the issue wasn't resolved for the person reporting the problem in the link above, but because the outage is minimized, and not being logged it is going unnoticed.

View 30 Replies View Related

Cisco Switching/Routing :: 3750 Populate All Switch Port With 100 Filter List

Oct 27, 2011

If i fully populate all switch port (Cisco 3750 series) with 100 filter list on each port is it recommendable.

View 4 Replies View Related

Cisco Switching/Routing :: 3750 - Configuring Multiple VLANs For Single Port

Apr 11, 2012

I would like to configure a 3750 switch port to be able to use two vlans. I know you can do this with a voice and data vlan, but what about two data vlans ? Say I have two devices, one on a 10 subnet and the other on a 172 subnet, but i only have one wall jack for both devices to plug into. So I use a mini switch to connect both devices and connect the switch to the wall jack; and of course this all leads back to one switch port. When I go to enter the switchport access vlan 172 cmd, how would I also make it so the device on the 10 subnet could route out ?

View 9 Replies View Related

Copyrights 2005-15, All rights reserved