Cat 3750 duplicating packets

I am using "monitor session" to mirror traffic to a monitor port, when I mirror a VLAN to the monitor port the switch duplicates every packet it mirrors with the duplicate being 7 microseconds behind the first.
The monitor session works as expected when I mirror an physical port to the monitor port.
Cisco Internetwork Operating System Software
IOS (tm) C3750 Software (C3750-I9-M), Version 12.1(19)EA1d, RELEASE SOFTWARE (fc
1)
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Mon 05-Apr-04 22:40 by antonino
Image text-base: 0x00003000, data-base: 0x007CBC3C
ROM: Bootstrap program is C3750 boot loader
BOOTLDR: C3750 Boot Loader (C3750-HBOOT-M) Version 12.1(19r)EA1b, RELEASE SOFTWA
RE (fc2)
IHPC3711 uptime is 4 weeks, 1 day, 21 hours, 21 minutes
System returned to ROM by power-on
System restarted at 12:10:14 UTC Wed Mar 8 2006
System image file is "flash:c3750-i9-mz.121-19.EA1d/c3750-i9-mz.121-19.EA1d.bin"
cisco WS-C3750-24P (PowerPC405) processor (revision C0) with 118776K/12288K byte
s of memory.

Are packets your seeing sourced and destined to the same vlan? If so, that is not duplicate, it's a mirrored packet from the source in the same vlan and the destination packet to the same vlan. So, you have two packets, one coming from the source host gets mirrored and then that same packet gets mirrored again as it now see that it's destined to the device in the same vlan. In other words, the rx and tx of the same packet is being mirrored and of course it's the same packet. Try either rx or tx only and see if you no longer see the duplicate packets. with span in both directions having two copies of the same packet is normal.

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CoS/DSCP to queue mapping in Cat 3750

Hi..
Cat 3750 supports mapping of CoS to queue as well as mapping DSCP to queue.
WOuld like to understand which one will the switch use when actually placing packets in the queue..
thanks
Eng Wee

My apologies, that was not a very good explanation :-)
Here is what really happens:
- when a frame is received on a port, the switch maps the CoS or DSCP in the packet to a QoS label to distinguish one kind of traffic from another. If the port is set to trust CoS, the CoS value is used to generate the QoS label. If the port is set to trust DSCP, the DSCP value is used to generate the QoS label.
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Paresh

CAT 3750 and WCCP?

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Is WCCP supported in CAT 3750?
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Multicast: duplicated packets on nexus 7k with vpc and HSRP

Hi guys,
I'm testing multicast deployment on the lab shown below. The sender and the receiver are connected to the 6500 in two different vlans. The sender is in vlan 23 and the reciever in vlan 500. They are connected to the 6500 with a trunk link. There is VPc between the two nexus 7k and the 6500.
Furthermore, there is HSRP running on the two vlan interface 23 and 500 on both nexus.
I have configured the minimum to use PIM-SM with static RP. The RP is the 3750 above the nexus. (*,G) and (S,G) states are created correctly.
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Indeed, I'm sending one flow, the two nexus receive it (one from peer link and the other from the 6500) in the vlan 23 (for example 25 packets inbound).
But when the flow is routed in the vlan 500, there is 100 packets on each interface vlan 500 on each nexus in outbound.
And when monitoring all physical interfaces, I only see 25 packets outbound on the interface linked with the receiver and the overflow isn't outgone.
I have joined the graphs I obtain on one of the nexus for the vlan 23 and the vlan 500. Netflow says the same things in bits/s.
Had someone already seen that? Any idea about the duplication of the packets?
Thanks for any comment,
Regards,
Configuration:
Nexus 1: n7000-s1-dk9.5.2.7.bin, 2 SUP1, 1 N7K-M132XP-12, 1 N7K-M148GS-11
Nexus 2: n7000-s1-dk9.5.2.7.bin, 2 SUP1, 1 N7K-M132XP-12, 1 N7K-M148GS-11
6500: s72033-adventerprisek9_wan-mz.122-33.SXI5.bin (12.2(33)SXI5)
3750: c3750-ipservicesk9-mz.122-50.SE5.bin (12.2(50)SE5)

Hi Kuldeep,
If you intend to put those routers on a non-vpc vlan, you may create a new inter-switch trunk between the N7K and allow that non-vpc vlan . However if those will be on a VPC vlan, best to create two links to the N7K pair and create a VPC, otherwise configure those ports as orphan ports which will leverage the VPC peer link .
HTH
Jay Ocampo

Cat 3750-Span (Port Mirroring issue)

Hello team
I am facing port mirroring issue in my setup. Details of the setup are mentioned below
Setup--
Stack of 4 catalyst switches WS-C3750X-48P running software 15.0(1) SE3 .Approximately 12 vlans are configured in this setup and port mirroring is done for all vlans with destination configured as single Gig Ethernet port...The setup works fine from mirroring perspective for 3-4 days and after that machine connected to destination port stops getting data.
Observations-
It has been observed that during the issue, the port configured for mirror destination has lot of packet drop/input errors on the port statistics.
If we configure only TX packet mirroring, it works for 8 -10 days
If we configure TX & RX packet mirroring, it works for 2-3 days
Testing done
Tried clearing counter on destination port but no success (mirroring doesn’t start)
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We need to reconfigure the mirroring configuration after removing the mirroring config from the switch. Once the same is done, mirroring starts working.
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1-is there any HW limitation for the switch (destination port not capable of handling mirroring traffic)
2-is there any software related issue?
3-what can be permanent resolution for the same..

Hello
We have tried this previously but found same result.
1- we deleted the monitror session and recreated again with same session number
2-we deleted the monitor session and created new session (session id diffrent ) with same config..
in both cases its working for 3-4 days..

Cat 3750 Switch: Dynamic vlan assignment

Hey guys,
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aaa authorization network default group radius none
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switchport mode access
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dot1x port-control auto
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dot1x reauthentication
dot1x guest-vlan 17
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spanning-tree portfast
radius-server host 172.17.1.1 auth-port 1812 acct-port 1813 key xxxxxx
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How to do NAT on cat 3750 switch?

give me an example or a link
thanks

Hi,
NAT is not supported on the 3750s. Here is a link that confirms that:
http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_guide_chapter09186a00802c10bd.html#wp1031988
Pls do remember to rate posts.
Paresh

Re: Cat 3750 Stack Management

Hello,
I am building a few 3750 stacks with three or more units, I want to be able to poll/monitor each individual switch in the stack but as it only has 1 ip associated with the stack, how can I do this? I am blind to a switch going down in the middle of the stack. I saw this in a four-year-old forum, but I say no specific resolution.

All stack management happens through the commander. The stack looks like a huge switch. If you want to monitor a specific switch's interfaces you can. They will be numbered as *EthernetX/0/Y, where X is the stack member number and Y is the interface number. CPU utilization can only be monitored on the active stack master, though. Inventory can be obtained from each stack member using ENTITY-MIB. Environmental data can be obtained for each switch using the CISCO-ENVMON-MIB.

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please advise, I am probably not the only one, but I have come to realise that 15.4W provided by switch ports on 3560/3570 catalysts is not sufficient to power up an AP1252-AG dual radio device. I have read the spec and it says that a dual radio AP requires 16.9W, but a single radio AP will consume/need 12.95W plus a little more depending on the ethernet cable length. As a test I physically removed one radio from the AP1252-AG and tried to power it up via poe port on switch. The AP powered up OK with just one radio module installed.
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In your case, if you have a controller, Aps need to talk to the controller, and the controller doesn't have any radio anyway, so you need cables to connect to your controller. If it is a 2100 controller, you can forget the switch and connect your APs to the controller.
If you have a 4400 series, you need a switch as APs cannot connect directly to 4400 controllers.
Cheers
Jerome

How to configure cat 3750 to support ssh2

hey,
I'm trying to configure, my catalyst 3750 to support sshv2 im running IOS c3750-ipbasek9-mz.122-25.SEB2.
what commands do I need to enter on the Switch? I got a pdf from cisco showing how to do it. but I don't quite understand it. Right now my switch is just using telnet. I want to configure it to support telnet, sshv1 or sshv2.
Also all the switches use tacacs as well
thanks alot!

This should do it..
aaa new-model
username cisco secret cisco
hostname
ip domain name
crypto key generate rsa (this one is interactive)
line vty 0 4
transport input telnet ssh
SSHv1 or SSHv2 is dependant on which version of the IOS you use...
Check this document:
http://www.cisco.com/en/US/tech/tk583/tk617/technologies_tech_note09186a00800949e2.shtml

Cat 3750 and EEM

HI,
I have a 3750 as below and it doesnt seem to have eem commands on it.
I thought EEM was supported for this platform,IOS version and Package level?
Any Ideas?
Cisco IOS Software, C3750 Software (C3750-IPBASEK9-M), Version 12.2(53)SE2, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
System image file is "flash:c3750-ipbasek9-mz.122-53.SE2.bin"

Is this definitely not a defect that the CLI commands are disabled?
I have the same issue and when i look at the processes i get this:
#show process | inc EEM
   9 Mwe 1CF14D8          49       971      50 7708/9000    0 EEM ED Syslog
57 Mwe 1CD7DB0      286447   1855661     154 7700/9000    0 EEM ED ND
58 Mwe 1CC7330           0       187       0 7676/9000    0 EEM ED Identity
59 Mwe 1CC7330           0       333       0 7668/9000    0 EEM ED MAT
282 Mwe 1CDE97C           0         2       0 7852/9000    0 EEM ED Routing
288 Mwe 1C82058           9        53     169 4556/6000    0 EEM Server
289 Mwe 1CA2888           0         2       0 5100/6000    0 EEM Policy Direc
291 Mwe 1CC7330           0         2       0 7820/9000    0 EEM ED CLI
292 Mwe 1CC7330           0         3       0 7824/9000    0 EEM ED Counter
293 Mwe 1CC7330           0         3       0 7820/9000    0 EEM ED Interface
294 Mwe 1CC7330           0         3       0 7824/9000    0 EEM ED IOSWD
295 Mwe 1CC7330           0         3       0 7820/9000    0 EEM ED None
296 Mwe 1CC7330           0         3       0 7824/9000    0 EEM ED OIR
298 Mwe 1CC7330           0         3       0 7824/9000    0 EEM ED SNMP
299 Mwe 1CC7330           0         3       0 7824/9000    0 EEM ED SNMP Obje
300 Mwe 1CC7330           0         3       0 7824/9000    0 EEM ED Ipsla
301 Mwe 1CEE868           0         2       0 7856/9000    0 EEM ED SNMP Noti
302 Mwe 1CC7330       11653    150780      77 7624/9000    0 EEM ED Timer
Looks like all the event detector processes are running and getting invoked. The syslog one has been invoked 971 times for example.
Does the auto smart ports feature use all of these? Also the policies are for eem 3.2 not eem 2.4 which is what is in the feature navigator. Would be really nice to be able to have cli access to these processes seeing as they are running.

Web Authentication on Layer 3 interface with Cat 3750 - doc is wrong?

Cisco 3750 with IP Service Image 12.2.55
Trying to enable Web Authentication on Layer 3 interface:
ip auth-proxy name bp_auth_proxy http inactivity-time 60
interface GigabitEthernet1/0/5
no switchport
ip address 192.168.1.27 255.255.255.0
ip access-group 101 in
ip admission bp_auth_proxy
last line fails:
% This config is not supported on this platform. Try configuring a new rule.
I also tried to set this on vlan interface, same result.
The line works on layer 2 interface, but this is not what I need.
Doc says everything must work with Layer 3 i/f, since 12.2.52:
http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_55_se/configuration/guide/swwebauth.html#wp1104204
Am I doing something wrong?
Thanks a lot for help!
Sergey

Hi, I'm having the same issue issue in 12.2(55)SE6 IP services, did you ever get it working or find a work around?
Web-Auth-TestSW1(config-if)#int fa3/0/1
Web-Auth-TestSW1(config-if)#no sw
Web-Auth-TestSW1(config-if)# ip address 10.x.x.x 255.255.255.128
Web-Auth-TestSW1(config-if)# ip admission webauth1
% This config is not supported on this platform. Try configuring a new rule

Cat 3750 with Voice VLAN and Dynamic VLANs

Morning,
Has anyone had any success with configuring a Catalyst 3750 with a Voice VLAN (Cisco phones) and 802.1x dynamic VLANs?
Is a RADIUS server able to provide values to change the native vlan?
Is there a decent tech note knocking about for configuring 'dynamic VLAN assignment through MAC addresses'?
Thanks,

Voice VLAN's don't require trunk ports to be configured (unless you are talkling about 2900XL/3500XL switches). Cisco added the ability to trunk a single 802.1q VLAN down an access port in addition to the access vlan - so in 2950 or above the only config you need is:
interface FastEthernet0/1
switchport
switchport mode access
switchport access vlan 10
switchport voice vlan 100
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interface FastEthernet0/1
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk native vlan 10
switchport trunk allowed vlan 10,100
The only difference is the CDP message with the first config will advertise the Voice VLAN capability and the tag.
With the older 2900XL/3500XL switches you had to configure the interfaces like the second example (plus adding the command switchport voice vlan xx for CDP to inform the IP Phone of the voice vlan).
QoS is not detailed anywhere here and that obviously plays an important role with voice.
In your scenario I am not sure ACS can do what you describe as this will require 802.1x supplicants on the client PC's (I may be wrong here and I do remember someone talking about switches being able to do an 802.1x 'proxy' using the MAC address on behalf of non 802.1x capable devices). This seems to me more of a VMPS application.
Personally I would reconfigure the network each time and charge the occupants a small fee for network setup.....
HTH
Andy

Cat 3750 duplicating packets

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