Cisco WAN :: Port Security Between Two Switches 3750 Or 3560 Using Trunk
Sep 2, 2012
Is it possible to use Port Security mechanism between two switch (3750 or 3560) ports while trunk has been configured? If it's not possible, is there any other way to ensure that no other Switch can be connected other then the one switch which has been configured/placed by a network engineer?
We have 7 3560's in 7 different locations connected to our providor for wan access. Our provider has given us a copper cable at each point and we have connected it directly to our 3560 switch at each location. Each port is configured the same way at each location. Each switch is running eigrp.All of the switch ports on each switch are configured as a trunk and vlan 299 had the ip address for the eigrp connection: [code] This setup is working as each switch see's all of the other switches as an eigrp neighbor. We have also made sure that the switch at our head office has spanning tree priority for vlan 299.
So the problem is, if there is a change in the topology at one of the locations it usually causes one or more of the other connections to go down for some reason. We just cannot pinpoint what is causing this change. There are no log's or anything other than an eigrp hold time expired message.?
Is there really any reason why you wouldn't use spanning-tree portfast on a trunk port other than a trunk between two switches? We have it enabled on all ports except for the fiber trunk between two non-stacked switches and the trunk ports connected to our Astaro firewall.I'd like to enable it on the ports to the firewall unless that would cause issues.
My group has recently started configuring traps on our switches to alert us of issues as they arise vs. waiting for the Helpdesk to receive user complaints and then responding.We have successfully configured the 2950 and 2960 switches to alert us when a port-security violation happens. However, the 3750 switches refuse to fire the port-security violation traps. The 3750's will fire an errdisable trap when the port goes down though.
And here is the output of the port-security debug:
2522070: Oct 21 16:37:04: %LINK-3-UPDOWN: Interface FastEthernet1/0/45, changed state to down 2522089: Oct 21 16:37:05: %PM-4-ERR_DISABLE: psecure-violation error detected on Fa1/0/45, putting Fa1/0/45 in err-disable state 2522100: Oct 21 16:37:05: %PORT_SECURITY-2-PSECURE_VIOLATION: Security violation occurred, caused by MAC address 0012.3f07.95d3 on port FastEthernet1/0/45.
All of the 3750's are running C3750-IPBASEK9-M, Version 12.2(53) SE2. Wireshark also shows the errdisable traps, but no other traps so I've ruled out the traps being missed. All of the switches have been reloaded and power cycled.
I have a pair of 3560's configured with dot1q trunks between them carrying a number of VLANs.
Once deployed there will be a requirement for these physical trunks to be disconnected from time to time. Knowing that this is inevitable I am trying to minimise the period of time for the trunks to recover once the physical connectivity is reinstated.
All of the VLANs on the switches are configured for Spanning Tree Rapid PVST. Current time for the trunks/VLANs to come up is around the 4 second mark.
Any way to test in a lab what would happen if a tech mistakingly added "switchport voice vlan XX" to a trunk port? I am try to do some RCA on an issue and this has been identified as a possible cause by one of my techs.
The config is Switch1------Switch2--------Switch3 Each interswitch connection is configured as a dot1q trunk with all vlans allowed. The link between switch2 and 3 is where switchport voice vlan 10 was added. Switch1 is a 3750 and 2/3 are 3560's.
I have client who has two distant offices with 3750 L3 as core (do all vlan routing for local office) and multiple L2 access switches with multiple VLAN’s connected to it. First 3750 is hub also connected to internet, second 3750 is spoke and acting as a router on stick. We have eigrp configured on both side ISP provided client 100Mbps link as a trunk with two vlan; vlan10 for voice and vlan20 for data. We assigned two small subnets to these vlans 10.15.17.0/29 and 10.15.17.9/29. Hub addresses are 10.15.17.1 and 10.15.17.9 respectively. How to force voice over VLAN10 and data via vlan20, but still do some load balancing? How to setup default route on second (router on stick) switch?
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 end flash:c3750-advipservicesk9-mz.122-46.SE.bin
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.
I have a 3750 as a core and have a series of HP Procurve switches that are daisy chained using one port. I have two vlans on the port now (6 &9) and everything works fine, all switches communicate and end devices on the switches are also talking. There is a requirement to add a device towards the end of the chain which requires it to connect using Vlan1. Once I add Vlan1 to the port onthe 3750 I lose connectivity to all the HP switches.
We had a core switch (Cisco 4503), distribution switches(Cisco 3750) and access switches in our network and consists of many vlans. Almost all vlans uses DHCP Pools. But for few vlans DHCP is not yet configured due to initial design poblems. Recently one of the rogue user in vlan 1 connected to one of the access switch send rogue arp packets to the network (suspecting arp packet with interface vlan 1 ip of core switch with wrong mac-address (gateway ip of vlan 1)) and resulted in a prolonged network outage for the vlan 1. Any way we are going to seggregate vlan 1 into different vlans, but before that we need a temporary plan to block such kinds of attack like enabling DAI in the switch. I have checked the DAI implemenation feasibility with my knowledge and found that it is not possible to configure to the access switches(Cisco 2960) in which the user directly connected. But found that Distribution switch connected to that particular access switch seems to be able to configure since DAI commands are available to configure in switch.
Is it possible to block ARP packets with the interface vlan 1 IP Address with rogue mac-address by configuring DAI in the above mentioned Distribution switch and the port connected to the mentioned access switch?
trunk port connecting but not allowing access to tree; i connected 4506 port to 3550 port; and i set both to switchport mode dynamic desirable; the 4506 port was set with switchport mode access and switchport mode access vlan ?; i used the command default switchport access vlan to remove the vlan; the ports are up but as I stated I cannot connect ot our workgroup tree
I am using 3560 switch senerio is that we have dhcp server on and I want that switch filter mac on whole switch ports not on a some port. Switch only give IP to the mac whcih is in mac table of switch/particular which we enter manually.I have read chapter 62 of port security but it doesnot fulfill my requirements.I am also using 3com 5500Ei switch in which we dont have to bind a mac on every port, we just enter a mac in the switch and it filter itself by using simple commands.DHCP server is not in our hands, we cant do any things there.
We have a couple of Cisco switches and connected a (Windows 7) laptop to one of them and it gets its IP address from a DHCP server.I can now ping the IP from all of the switches, no problem, also not when I log on to the core switch in the same VLAN as both notebooks. But from my (Windows 7) laptop, which is in the same VLAN as the target laptop, I cannot ping it.
I checked, default gateway is good on both sides, as are DNS servers.
I have a 2611XM that I am using as a terminal server for my lab setup. Async is using octal cables. It works great with routers of all different models, but when I connect a switch of any model, it does not work. The connectivity LEDs don't even light (they do for the routers). The switches in question are 3750s and 3560s.
I have tried straight through from the octal cable to the console port of the switch, as well as a rollover with a converter, no luck. This does seem to be independent of configuration on the console port - even before the console port of the routers were properly configured, I at least had indication of physical connectivity.
I have more than 20 Cisco switches in my office which is basically a soap manufacturing factory. The switches include Cisco 2950, 2960, 3560, 3750 etc. We have routers also which include 2821, 2951 etc. We also have Cisco WLC 2125 and LAP 1262 series. Sometimes all these devices management comes very tough to us.
We need to log on to different devices for troubleshooting/network management which sometimes becomes very tough to us. So I wonder if there any Cisco applications or tools by which we can centrally manage all these devices.
For many years we've had the following vlan and port security config on our 3560s: [code] This has worked great on 12.2(37)SE1, 12.2(40)SE and 12.2(46)SE. However since 12.2(50)SE, and I've tried all the versions since then, we have a problem with 7900 phones and ATA186s taking upwards of 20 minutes before they can get a valid IP number.The problem on the newer IOSes seems to be related to the inactivity aging.On the older IOS versions the mac address of the voice device appears on the voice vlan straight away.
On the newer IOS versions the mac address of the voice device appears on the DATA vlan and seems to be stuck there until the inactivity aging removes it. It then gets re-learned, sometimes on the voice vlan, and sometimes on the data vlan. If you're unlucky and it gets re-learned on the data vlan you've got to wait until the inactivity time ages the address out again. Repeat until the mac address eventually gets learned on the voice vlan. I don't want to be stuck on 12.2(46)SE forever.
I have 2 3560 switches that are running 12.2(25)SEE2. Port security is enabled on some of the ports. Whenever there is a power failure, when power is restored, 1 port on each switch goes to err-disabled. The mac address that causes this is a valid address for that port. Below is the configuration on one of the ports.
I've been fighting what seems to be an increased number of outqueue drops on our core stack and edge switches for the last 3 or 4 weeks.(The core consists of a stack of 5 3750s in 32-gig stack mode. The wkgrp switches are 3560s. all are at 12.2.52) The wkgrp switches are directly connected to users. We use Nortel IP phones with the phone inline with the user PC. auto-neg to 100/full. [code] However I have tried turning off QOS on a couple of workgroup switches (no mls qos, but left individual port configurations the same) but am still seeing drops.Since I have disabled qos on the switches in question (no mls qos) (not the core tho) I am presuming these commands have no affect on the switch operation and therefore cannot be related to the problem. With QOS turned off one would presume that it is general congestion - especially at the user edge where busy PC issues might contribute. So I wanted to see if I could see any instances of packets in the output queues building up.
I wrote some scripts and macros that essentially did a snapshot of 'show int' every 20 seconds or so, and looked for instances of 'Queue: x/' where x was greater than zero.What I found after several days of watching the core stack, and a few of the workgroup switches that are most often displaying the behavior, was that I NEVER saw ANY packets in output queues. I often saw packets in Input queues for VLAN1, once in a great while I would see packets on input queues for fa or Gi interfaces, but NEVER on output queues. [ code] Additionally, when I look (via snmp) at interface utilization on interfaces showing queue drops (both core and wkgroup), they are occurring at ridiculously low utilization levels (as low as 4 to 8%). I've tried to look for microbursts between the core and a wkgroup switch where the core interface was experiencing drops, but haven't seen any (using observer suite). [code] While the queue-drop counts aren't critically high at this point, they are happening more frequently than in the past and I would like to understand what is going on... In most cases, no error counters are incrementing for these interfaces. Is there some mechanism besides congestion that could cause output queue drops?
I was wondering if there is a workaround to have a mac access-list bond to a port security violation action our need is the following: we have a range of 10 mac addresses that can use any port on the 3750, we only want to allow those ones yet we also need to tak action if a denied mac appears on any port of the switch.the only work around I found is to basically go into a port-rage mode and list all the allowed mac addresses under all the ports of the switch. I would also add to that a port violation action. did not test it but should work. problem is, it would be a huge config.I did read that we can create a mac access list and then bind that mac to physical ports wich will actually simplify our solution yet I did not find a way to bind the mac list with a port violation action.
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.
I have 3560's in my current environment, operating in the core/distro/access layers. The switches are in a star configuration, performs only layer 2 switching, and utilizes copper (no plans on moving to fiber).
With a fairly limited budget, I've been contemplating on upgrading the central node to a stacked 3750X to eliminate that single point of failure, and trunk the rest of the 3560's to the stacked switch. I wanted to be sure that the 3750X switches will be right for my environment (90-100 hosts), and if what I explained above is a good solution.
I'm also looking like to upgrade 6-7 of my servers (and SAN) with 10GB network cards. Do the ports on the 3750X have port densities capable of 10GB? If not, what switches provide that capability?
We have the port on the switch set like this: switchport port-security maximum 25 switchport port-security switchport port-security aging time 2 switchport port-security violation restrict switchport port-security aging type inactivity
In case a device connected to the port is inactive for more than 2 minues ( aging time ) the first frame/packet the device generates arrives to the port on the switch, but the switch does not forward it to the appropriate port ( discards it or whatever ).
So far I tested on 1 30 WS-C3750E-24PD 15.0(2)SE2 C3750E-IPBASEK9-M 2 30 WS-C3750E-24PD 15.0(2)SE2 C3750E-IPBASEK9-M 3 52 WS-C3750G-48PS 15.0(2)SE2 C3750-IPBASEK9-M
When we remove port security from the port, it works perfectly fine, as expected.
It seems this is not HW or IOS version related. It seems it is not a stack synchronization issue, it does not matter if a device is connected to the first or other stack member. I tested on C3560 too, here there are no problems, so seems it is 3750 related.
I have a Cisco SW ( 3560 ) with one Trunk link to my router ( 7606 ), Trunk link is fully utilized so i need to add 2nd Trunk.Shall all move some customers from old trunk to 2nd one and create a new subterface for them ?I am think if i can create bundle and add subinterfaces under this bundle ?Add two GE ports to be memeber of this bundle ?
I recently was asked to turn a routed link between our HQ and our DR Site into a trunked link to allow us to span our main Server VLAN up to the DR Site.I was informed by the ISP that owns the 100Mb Leased Line between the sites that the link was configured to pass dot1q traffic and I should just have to configure my links at either end as trunks to get the link to come up.
There is a Cisco 3560 at either end with Layer 3 routing enabled (obviously as this was a routed link previously).So, I scheduled an outage and configured either end as a trunk links as follows and repointed any routes from the /30 routed addresses to the management addresses of the switches on either side:
***For info VLAN 15 is the DR Site and VLAN 11 is the Server range at our HQ and was available on the connected switch***
We have purchased 3 no CISCO SF300-48P (Access Switches) with the interest of setting up a new laboratory consisting of 120 desktops. We currently have a CISCO 4507R (Core Switch) and a CISCO 3560 (Distribution Switch) for the campus wide network. Our network is developed with various VLANS to support Internet and Intranet facilities. The new lab need to be incorporated in to the Campus wide network with a new VLAN ID. But problem is while trunking the CISCO 3560 (Distribution switch) to the CISCO SF300-48P (Access Switch) communication does not happen. While, surfing the internet and various doc's say that SF300 uses GVRP instead of dot1q trunking.
I need to create a trunk between a Cisco 3560 and a Juniper EX4200I am perfectly happy with the the Cisco side and want to only allow 1 vlan across the trunk, which I was going to configure on the 3560 side. Any experience on trunking to a Juniper Ex4200.Looking at the Juniper side it looks like I just set the port as a L2 uplink.
A client of ours has installed an SG300-24P switch and would like to setup a LAG between the SG300 and the 3560 switch we manage for them. They would like the LAG to also pass the voice and two data VLANs currently in use; 5, 10, and 100 respectively. I configured the two ports as an Etherchannel with trunking on the logical port, but no luck. I reconfigured as follows:
interface GigabitEthernet0/1 switchport trunk encapsulation dot1q switchport mode trunk channel-group 1 mode active end
I see no output when I do show lacp nei. At this point the client is looking to use for the configurations to use as he does not know how to setup the SG300 and it is a switch I have never dealt with. I have found some configurations that I believe would allow a single VLAN across, but nothing I believe will allow the LAG to pass all the VLAN's.
if i have this config: switch port mode trunk trunk aloved vlan 50
will travel over this trunk untagged packets? For eg the V LAN 1 is by default native V LAN without tag. If i have created a bog ring with catalyst 3560x switches with no spanning tree on V LAN 1 can be the case of this config a loop ??? I am using upper config on interfaces that are connected the switches together in ring.
Other interfaces on switch have this config: int range 0/1-4 switchport mode acc switchport acc vlan1
int range 0/5-24 switchport mode acc switchport acc vlan50
I am using vlan1 just for local switching without connection to internet! I am asking just because i have this king of messages in logs:
%CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet1/0/27 (1), with SW3560x_BR8874 GigabitEthernet1/0/19 (50).
GI 1/0/27 and GI 1/0/19 have this config: switchport mode trunk trunk aloved vlan 50
I have applied port security in one cisco switch and i have enabled port security in one port.I have applied port security as sticky and applied "restrict" on violation of the portsecurity.Now i have connected a PC to that switch port. Later i have connected another PC. The packets got dropped. But when i connected the original PC again, the packets flow started again.So, i have a doubt. Will the packet flow get establish, when the original PC is connected again to a port which is applied with port security violation "Restrict"?
I have a 3750g connected to a "core" switch stack of 7 other 3750g's via 2 GigE ports in a trunk. This is currently in a switchport mode access port- channel so only the default vlan data is sent over. Now we have a need due to physical location of these switches, to allow vlan20 (DMZ) from this 3750g to the switch stack. I will configure a few ports on the switch stack for vlan20 and they need to be able to talk to the stand alone 3750g.To do this I will change the port channel on both endpoints to
-switchport trunk ecapsulation dot1q
-switchport mode dynamic desirable
also making the appropriate change on the interfaces belonging to this trunk.My question is, now that its a trunk port that carries multiple VLANs, how much is the bandwidth reduced on that 2gbps link?I have a very active VLAN (10) on the stand alone switch, but on the core I'm not going to be assigning VLAN 10 to any ports. So does traffic from VLAN10 even come across the trunk (wasting bandwidth) if no ports on the core side are assigned to it? I really just need vlan 1 and 20 (for now).
I configured port security on my 2960 switches with the following commands: [code]
The problem is that when I should change someone's PC, first I disable port-secirity, then I clear all the mac addresses learned on the interface, then I plug the new PC and enable port-security. The new PC couldn't connect to the network and it's mac address has not be learned on the interface. Why?Which commands should I use to clear an old mac address and enable port-security with the new mac address.