Cisco Switching/Routing :: 3750 - Tagging Traffic By IP Source And Destination?
Dec 2, 2012
I want to know if there is way to tag traffic with DCSP tags without having to do all the other requirments of QOS setup. All i want to do is just tag traffic at different DCSP values via source and destination IPs. We do not have a need to be priortizing traffic on out internal switches. We just want to tag the traffic so our MPLS provider can distinguish the different types of traffic.
Our environments is primarily 3750s in all offices.
i would like to monitor traffic between multiple source ports to multiple destination ports on a nexus 7k. i lknow when you set up monitor session is between source and destination (laptop or traffic analyser) but is there a way i can set up between source and multiple destination ports and capture that traffic ?
We have 2 switches split across 2 datacentres connected via an interconnect. Over the past couple of days the interconnect provider's Cisco kit has shut down our port (err-disabled) due to a broadcast storm. They had the level set at 1 which I thought was a bit low. They say they tried to set to 2, then 5 but still kept tripping the storm-control feature so they set at 10. They say they've always had it set at 1% (on a 100Mb switch) and so we must be generating more broadcast traffic.
I'm trying to identify where the broadcast traffic is coming from. On our Cisco 3750 I've clear interface counters and when I do a sh run | i broadcasts there are a few ports which have what seems like a high broadcast count. The one port that is especially high and the only one tripping the storm-control feature (I've enabled on all our ports to try to identify where the traffic is coming from) is the port connected to the 100Mb interconnect. I've mirrored that port to another port and connected a server with wireshark so I can capture all the traffic across that port.
What I'm struggling to find is the source of the broadcast traffic.I have a few questions are these broadcasts layer 3 or layer 2 broadcasts. Also in the output below when it says broadcasts received is this inbound to the port i.e. from the connected device or is this a total of inbound and outbound broadcasts.
When I use wireshark and filter the capture on broadcasts (ff:ff:ff:ff:ff:ff) I see only 200-300 compared to the thousands the switch is reporting.If I filter on the broadcast IP address I also don't see the numbers corresponding to what I see in the show interface output.
GigabitEthernet1/0/1 is up, line protocol is up (connected) Hardware is Gigabit Ethernet, address is 0014.a93f.7401 (bia 0014.a93f.7401) Description: Interconnect MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 4/255, rxload 44/255 Encapsulation ARPA, loopback not set
[code].....
also I'm currently doing : monitor session 1 source int g1/0/1 both, and also tried just rx incase I just need to be looking at receive traffic but still nothing is standing out.
I have a requirement to bypass some specific traffic (with particular source to specific internet destination) in ACE 4710.
All the webtraffic (http and https) is configured to loadbalance to my proxies , i need to configure some specific traffic with source and destiantion to internet to byepass from this loadbalancing and directly got to outside interface .
Basically I am trying to use Wireshark to do a packet capture on a Nexus 5010. I want to do a monitor session on on the switch so I can capture from a source port to a destination port on the same switch. I can configure the source port but when I go to configure the destination port I get "ERROR: Eth102/1/4: Configuration not allowed on fex interface". I have tried to reconfigure this port as a switchport but "switchport mode access" command does not take. I don't want to make any changes to any other ports but this one.
I'm trying to get ERSPAN working with an ERSPAN source on a Nexus 5548 and the ERSPAN destination on a Catalyst 6500.
The configuration on the Nexus is as follows:
[...] interface loopback0 ip address 192.168.2.133/32
[Code].....
If I do a netdr capture I can see ERSPAN traffic sourced from the Nexus reaching the C6500, but there doesn't appear to be anything sent out the ERSPAN destination inerface (Gi4/6) and there's nothing being received by the probe connected to that interface. I know the traffic seen with netdr is definitely the ERSPAN traffic sourced from the Nexus as I've changed the TTL and DSCP values within the monitor session on the Nexus and can see those changes reflected on the C6500 netdr capture. The attached is a screen grab of the show netdr capture started with debug netdr capture soure-ip-address 192.168.2.133.
When I look at the interface I see it shown as up/down (monitoring), but no output or counters clocking up. If I run a local SPAN session on the C6500 it works fine.
I've tried changing the destination IP address from that assigned to the C6500 Loopback interface to an IP address assigned to a physical interface, but that still doens't work.
The hardware in the C6500 is WS-SUP720-BASE Hw version 3.2 with WS-F6K-PFC3B Hw version 2.4. The IOS version is 12.2(33)SXI6.
We have 2 6513 switches with SUP720/PFC3A and various POE modules and a 6748-GE-TX facing our servers. Additionally, we have a 4Gbps portchannel trunk interconnecting the switches. We have approximately 300 Nortel IP 1140e phones in use between the two switches.For the purpose of call recording, we've attempted to mirror the voice vlan using various approaches and have been met with limited success. We mirrored the VLAN using tx, rx, and both. When using both we appear to get duplicate packets at the destination interface.We seem to lose packets completely going in one direction or another for a given call. Packets are lost before they get to the destination interface?
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
At present we are having a 4900 series switch where we are running one monitor session.Additionaly we are in need of capturing VLAN traffic and set the destination to 2 * GE ports , both are in the same switch.Due to the limitation of two monitor sessions per switch , we thought of putting the destination ports as port channel but it looks like it is not supported.
There is a unicast flood on 3750 killing slow modem links. How to determine source MAC address of flooder? Is there a rate limit feature for it?
I know how to block it completely on port-level, but it breaks normal network operation. (when port goes down for some reason, it's learned MACs got flushed and since other hosts know MACs, they keep flooding untill their arp caches expire).
I have a situation which requires some non best practice stuff to be done. There is a box behind an ASA that has a lot of code that references public DNS names and therefore needs access to itself and a number of other boxes on the same subnet via the public DNS names (that obviously resolve to public IPs). This traffic is dropped on some pretty fundamental ASA characteristics.I know this isn't really ideal, and it should be handled by DNS nstead, but I'm in somewhat of a bind and need to know if the ASA can allow this traffic.I figure I could match the traffic and exempt it from state-checking and that would probably work, but it's not a very graceful solution.
I have a internal subnet 192.168.3.0/24 sitting behind an ASA firewal 8.2 and would behind accessing to web server 192.168.11.54 which sits behind the outside interface of the ASA firewall.The access would be like this:
1) 192.168.3.0/24 will be accesing to the web server http://192.168.11.54 2) We would like to translate the source 192.168.3.0/24 to the firewall outside IP address 3) We would like to translate the destination web server 192.168.11.54 to 202.90.197.146 as well
How to perform this simultaneous source and destnation address translation in ASA firewall 8.2? Could this be done in ASA firewall 8.2?
The Cisco ASDM or the event manager show wrong source/destination for teardown tcp messages:In this example the communication is an ssh session;from 1.1.1.1 -> 2.2.2.2 ssh and the connection is reseted by 2.2.2.2
The message build outbound is correct, i.e. source is 1.1.1.1 (message id is 302013)
But the teardown is incorrect, i.e. source for the connection is 2.2.2.2 which is definitely not true (message id is 302014)
Also there seems to be a documentation bug in syslog messages for ASA 8.4 since the message for the teardown 302014 is gone!
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.
Have a quick question regarding inter-vlan routing on a 3750. Overview of network is ISP --> ASA --> 3750 (acting as my core and default gw). I have 5 vlan interfaces on my 3750, all w/ 192.192.x.x subnets, a 6th w/ 192.168.100.x, and a 7th w/ 192.168.200.x. I have enabled "ip routing" on the switch and can successfully ping from subnet A to subnet B as long as both devices are using the correct DG for their vlan, which is the switch. I have a few ports that are trunked as well that go to ESX hosts which break out the vlans according to the subnet the vm should be attached to. The ASA is set to nat internal traffic for all the vlans.
Now my question: short of applying an ACL to each vlan interface to block traffic from other 192.192.x.x subnets is there a better way to accomplish this? I want my 192.168.10.x subnet to be able to reach all the subnets, but don't want 192.192.10.x to be able to talk to 192.192.20.x for example. I was thinking to create an acl like this:
access-list 120 permit ip 192.192.10.0 0.0.0.255 access-list 120 deny ip 192.192.0.0 0.0.255.255 192.192.10.0 0.0.0.255access-list 120 permit ip any 192.168.100.0 0.0.0.255 192.192.10.0 0.0.0.255
and then applying this to the interface for the appropriate vlan.
We have a remote office with a Cisco 3750-X switch with the IP-Services feature set connected via dark-fiber to a 6509-E at the corporate office. We plan on migrating the remote office to a new network (new acquisition) to subnet 10.10.10.0 on VLAN 20 which has an existing subnet of 192.168.100.0 and we would like to run both in parallel using their existing switches (Dell) and the new 3750-X.
I’m curious as to the best way to keep the traffic local between the two subnets using the 3750-X and if necessary put the 192.168.100.0 network on a VLAN. I thought about routing between the two networks via IP routing on the 3750-X but the new workstations default gateway is the 6509-E and existing workstations is a SonicWALL within the remote office. The default gateway for the new workstations can be moved from the 6509-E as a last resort.
I have 2 new 3750g devices in a small environment. switch1 acts as our collapsed core and has ip routing enabled, and is connected to a ASA 5510. There are 3 HP l2 switches connected to switch1 as well. switch2 is simply a server switch. switch1 and switch2 have a 2port etherchannel between them, and a vlan trunk carrying 4 vlan's. traffic between any 2 hosts on switch2 (same vlan) are slow. (average 300Mbits/sec) If I move one of those hosts to switch1, speeds increase by 3 times. (average 900 Mbits/sec). Additionally, traffic between any 2 hosts on switch1 are quick. testing is done with iperf as well as timing 1gig file transfers.
I don't see any errors or drops anywhere, and there are no other symptoms other than slow transfer beteween hosts on switch2. I just got 2 more of these 3750's to put in a 2nd site that we have, put a quick configuration on them, and have the same result. Other than switch1 having ip routing enabled, the configs are pretty much identical.
we have three separated network segments going to one Cisco 3750 switch all is L2 .. from this switch is 100 mbit uplink.we need to apply some Qos mechanism not to saturate line by traffic from one network.. Configuration from various reason CANNOT be done on switch where 100Mbit line is terminated.. so all must be done on SW1,2,3..Correct me if iam wrond but as switches doesnt see traffic from other network iam affraid only think we can do is limit bandwidth on links going into SW1,2,3 to 33 Mbit.I found commad srr-queue bandwidth limit.But links going to SWs are 1Gbit so if i force bandwidth to 10% (minimum what command allows) its 100 Mbit..If I force speed on those links to 100Mbit and than apply srr-queue bandwidth limit to 30% doest it work.??. Will srr-queue bandwidth limit speed to 30Mbit?? Or srr-queue bandwidth limit is calculated from maxim speed of interface?
I am trying to mark http packets from a web server with DSCP ef, but when I am doing a traffic capture all http packets have tos 0x0.I am able to mark UDP and ICMP packets originated from this server, but not any TCP traffic.The web server is in VLAN 20This is my config mls qos ip access-list extended MARK-HTTP-ACL permit tcp host 10.10.10.10 eq www. [code]
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.
Unable to limit traffic on catalyst 3750 gigabit ports it has fiber modules,
I want to limit traffic 2mb per port
I have tried srr-queue and policier but it is not working and there is no ratelimit command under any interface, Applying policy to output is not supported of the interface
policy-map rate-limit class class-default police 2000000 8000 exceed-action drop int gi1/0/3 service-policy input rate-limit
Actually i have a design from my customer who have ( Cisco core switch 3750 (allports fiber ports) which is connected to L2 switches , these switches carry servers and end users .the only routing protocol on the access switches is static route ,
My question how can i route the traffic from the server to the end user , as the the server is not direct connect to the core switch.
We are using Cisco 3750 switches in our environment as distribution switches.We currently use to police inbound traffic, but we need to find a solution to limit inbound traffic per IP.Something like this “Inbound traffic for each IP can be maximum 1 Mbps” This can be done having, one ACL and one class-map for each IP, but in my situation is not a practical solution, because we have more than 500 IP’s on that site.
Is any way to accomplish this without writing 500 ACLs and 500 class-map?
I am aware that the 3750 switches are not able to support Netflows, so I have created a SPAN port and spanning traffic from a specific port. I would like to create a seperate VLAN and trunk the traffic from the SPAN port down to the 6509 switch and then capture all the traffic for that VLAN on the 6509.
I have One switch 3750 and many switch 2960 c.I use one ASA 5510 to reach emote branche site (vpn conexion).I use one router 1841 for internet conexion.Router 1841, ASA and catalyst 2960 are connected on the 3750.Default gateway of all user is ASA IP
I configured Vlan 3750 and it work.Now I need to implement security : permit/block specific traffic between vlan [code] From vlan 72 I cannot have remote access on computer in vlan 34 and I cannot ping computer in vlan 34.
I am trying to setup a network using Cisco 2960 switches with vlans configured. One vlan will handle video coming from four cameras that are connected to another 2960.
We have four cameras feeeding one port each on a 2960, that 2960 in turn feeds one port on the main 2960 which is the video vlan for that site. From the site it goes back to a Cisco 3750 to be sent over to a Sonicwall firewall. If we connect to the 2960 that the camera are connected to we can see the video, but not on the main site 2960.
On a router I can use IP Accounting or Netflow to see what kind of traffic is moving over an interface. Are there any tools on a 3750 switch with a routed interface which would tell you who is hogging the bandwidth on that interface?
I have catalyst 3750 I want to controle traffics on every port I have tried Frame-Relay Traffice shaping and Quality of service but there is no support for these commands in the switch.do we have any way to limit traffic on every port in catalyst 3750 and 2960 switches ?
We are trying to replace the CSS between our firewall and DMZ with a BigIP. Among it's other functions, it will act as the router between the firewall and the DMZ. To make this work, I need to assign vlan tags values for the vlans I create on the BigIP box and these must match the tags on the cisco switches (3550's) How do I find this information on the switch?
If you have a router with multiple direct vanilla FE (non trunked) interfaces on a switch trying to send QOS tagged packets to a wifi bridge several switches away does the trunking in the switched infrastructure mess with the qos tags if no qos is configured on the switches.
Does it depend on the switch? We have new 2960's running 12.2 and a few older 2950's running 12.1
Our enviornment includes 3560 switches and 2800 routers. We have a few remote offices using an application on TCP port 1677 that use far to much bandwidth. Our WAN provider can throttle and police this for us, if I can TAG this traffic, for example all Traffic from Florida using the Groupwise app on TCP uses TCP port 1677 and I want it tagged with CoS 3.
I have a 2960 switch connected to another. The I need to verify that vlan0010 on one switch is forwarding tagged traffic between the other switch it is hooked up to through the Gi0/1 port. How do I verify this? I have a server that's multihomed (Broadcom) on the other side an it is supposed to be on this vlan with one of it's network interfaces. We had a pwer outage and now it cannot communicate on this vlan. However, everything else on the vlan can reach all the other nodes accept this server in the front of my building. All the devices in the same room are linked to the same switch which has one port (fa0/17) on vlan0010 and can ping eachother just fine. The server is hooked to port 24 on my server room switch and Gigabit port one goes to a fiber converter all the way to the back. It then gets converted from fiber to cat5e again and links into the switch (2960) in the backroom.
