Cisco Switching/Routing :: 2 PE Routers Connected To Each Other Via 2960S And 3750 Switches
Mar 5, 2013
I have 2 PE routers connected to each other via 2960S and 3750 (non-metro) switches:
[PE1] -- [2960S] -- [3750] -- [2960S] -- [PE2]
I will be sending voice and data traffic between the two and my voice traffic will be marked DSCP EF & EXP 5.
Since the 2960's and 3750's can't match on the EXP bits, I am wondering if the "mls qos trust dscp" command still works. Is the 2960/3750 able to match on DSCP even though there's an MPLS header on top of the IP packet?
I'd like to avoid having to tag my VLAN traffic on the PE and rely on COS to achieve QoS in this case.
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?
A specific switch port which happens to be part of a 2 switch 3750 Switch Stack is seeing multiple CDP packets from 3 extra switch port interfaces that are not directly connected. Noteworthy is that the far end devices have the correct CDP entries and I physically confirmed at least two of those connections that lead to the switch "upstream to the culprit switch". Tricky part is that its production so room for maneuvering is limited. At some point I disabled all Ports save for the real uplink and the problem momentarily disappeared. Re-enable the interfaces problem resurfaces. Is there an explanation, technique to eliminate the culprit with minimal disruption?
I am troubleshooting a fiber connectivity issue.Now I have two switches, one is 3750, and another is small biz 300 series switch. Both switch has a single mode smf gbic. Now I have two swtiches face to face and connect with a single mode cable. Do you think if I would get a link light on? Both ports are no shutdown.
client originally connects to the 4500E, moves to the 2960s and then cannot connect back to the 4500E.My design is a 4500E (configured for routing) and a 2960s. The 2960s is trunked to the 4500E, no vlan pruning.
Tried;
- shut/no shut port on the 4500E doesn't work
- no result for sh ip arp | i (clients mac) or sh mac address | i (clients mac) on the 4500E
The only way I can get the user back online is removing the 2960s, not a desirable solution as other clients are on the 2960s.
I have a 3750 as core switch, adding 2 stacks of 2960S to connect. I want to establish etherchannel between the 3750 and each additonal 2960S stack, do the channel group numbers between the 3750 and the new 2960s have to match? 3750 has two channel-groups(1 and 2) already configured. Need to know, I would create 2 additional channel groups (number 3,4) for each of the etherchannels between the 3 2960S Stacks and 3750? OR channel-group # is local to the device.
I have a new Cisco 2960 S series switch with a basic configuration that needs to be uplinked or daisy chained to a Cisco 3750 switch. I am not getting any connectivity to the network with either a straight through or crossover cable. the port remains in amber but a 'show interface' indicates that the interface is up. I can manage the switch with a PC patched into any port on the switch with a static IP address. Must be something very simple that I am missing. Outlined below is the configuration.
I have 2 Catalyst 2960S (24 ports and 48 ports). Can I stack them using the Uplink connection instead of the stack modules. I know Stack module is the best option but it is kind of expensives (half price of the 24 ports switch) and I only need to stack no more then 2 switches.
I would like to use flexstack to stack two Cisco 2960S 48 Port switches (2960S-48TD-L) for redundancy. Each switch will have a single 10G uplink into our Nexus 7K. One switch in the stack will terminate to linecard 6 (N7K-F248XP-25) and the other switch will terminate to linecard 7 (N7K-F248XP-25). My question is how many flexstack cables are needed? Do I need only one cable or do I need two to connect the two 2960s ?
I have to add a 2960s PoE switch to an existing stack of two 2960s PoE switches. If The new switch has no configuration on it and the existing stack is broken by pulling te stack cables and then new cables are added and everything re-cabled correctly will the new switch assume the configuration from the stack without any issues?
If I have two stackable switches one switch uplinks to one 6509 core switch and the other connection uplinks to another 6509 core switch, and also the other stackable switch does not connect to the core switches. Because I am using hsrp and also we are not using vss then one uplink to the core is not in used only ones is so then how does creating an etherchannel between does two uplinks to both core switches benefit me in anyway such as more bandwith and using both uplinks at the same time or I'm I wrong?
If I have two stackable switches were only one stackable switch has two uplinks one uplink goes to one core 6509 switch and the other uplink goes to the other 6509 core switch can a Layer 3 etherchannel be used if each uplink go to a different core switch, by the way hsrp is running between both switches and also can you give an example how data will be routed from the stackable switch through the ethernetchannel to one of the core switch accross the WAN to another core switch?
In my customer having 3750 switch and they have simply assign IP address for vlan and enable telnet in switch and other things are same as default switch.In this switch they have connected 8 cisco layer 2 switches(6 managed and 2 unmanged switch) and approximately 5 servers connected in this switch.In a particular interval,users accessing File server are connected to 3750 switch become hanged for few min.This happen for some particular interval.users accessing this server becomes entirely hanged for few min,then i have configured port monitor cmd and i have installed one wildshark tool to host connected directly to that switch.
I am using a 3750 as a default gateway for multiple Vlans on a few 2960 switches. The trunk lines are configured and working and I have assigned ip addresses to each of the Vlan interfaces on the 3750. My issue is that I can only ping the ip address on the Vlan interface of the 3750 if I have a working computer plugged directly into the Vlan on the 3750. I only have 3 vlans on the 3750 that have hosts directly connected (vlans 2, 10 and 40) the other vlans ( 20 and 70) don't have any clients plugged into them on the 3750 but the hosts reside on 2 different 2960s that connect via trunk ports. How do I keep the vlan interface on the 3750 switch pingable when I don't have hosts directly connected in that vlan on the 3750? (yes, I have enabled ip routing on the 3750)
I have a simple design with 3750. I configured a route-map which define a next hop. I defined this route-map on a policy on a vlan interface.When I test some ping and a debug ip policy and it seems that my policy never match.Is there any mechanism that prevent the switch from using PBR? I think of CEF .
I have a simple design with 3750.I configured a route-map which define a next hop.I defined this route-map on a policy on a vlan interface.When I test some ping and a debug ip policy and it seems that my policy never match.Is there any mechanism that prevent the switch from using PBR?
Any method of forcing a non connected switch port LED to blink for a certain number of times regardless if there is anything connected.The purpose of this is we have remote 3750 switch stacks and quite often have to tell non technical staff to patch to a certain port. It would be much easier if we could say "Connect it to the empty port which just started blinking orange" as the port numbers are difficult for them to see in these locations.A similar feature is available in the ethtool package for linux which makes it really easy for identifying ports on servers. It would be great if a similar feature is available on Cisco switches.
One of the ports on the 3750 stack was configured for VLAN121. It was changed to VLAN40 and the configuration saved. Both VLANs exist in the switch configuration. As soon as a host was connected (in this case, a label printer) the port VLAN reverted back to VLAN121.
Switch A connects to Swich B and C using port channel. I am going to bring down one link on each.
switch A is server farm , switch B and C are core 01 and 02 . and all are 3750 switches.
1. what will be the impact on the network in terms of spanning tree recalculation 2. what duration are we talking about until the spanning tree convergence happens? 3.I plan to shut down the link from CLI to bring down the links
I have a small campus network using 3750 stackable switches and a 3725 router (see diagram below). Currently the 3725 router is handling inter-vlan routing for the campus and it looks like it's not able to handle the amount of traffic we're pushing. The router CPU sometimes hits above 90% due traffic load. What I would like to accomplish is move L3 process over to the 3750 MDF stack and the IDF1 stack. I am thinking creating SVI's on both MDF stack and IDF1 stack, run HSRP between the two stacks and may be do load balance traffic between the two stack as well.
Looking for feedback from other organizations that have large 3750 stacks. I've got one stack of (8) 3750's composed of (6) 3750G's and (2) plain 3750's. This particular stack is usually unresponsive to SNMP queries and often fails to write config when we make changes. After a couple tries it will finally go. Part of my probably here is likely the plain 3750's that always boot faster and come up as the master. I should manually set the master to one of the G's. What I'm wondering is who else has 7-9 3750's stacked and are they performing well for SNMP, telnet, etc? I've got another newer stack of 7 3750E's that I need to add one more switch to. Need to decide if I want extended downtime to break the stack up or just add the 3750X to make member 8 and hope it performs well. I have 50+ 3750 stacks working great on our campus.
We currently have a site with a very simple topology that uses a 3750X switch stack for a collapsed core. Everyday, the users have a conference call and experience poor voice quality.Its not bad when users call from several conference phones, but when everyone calls in on individual phones, there is choppy and almost inaudible voice quality experienced. The voice traffic flow would be as follows: Phone <-> 3750 switch <-> Voice GW We have packet captures showing that RTP packet loss is occuring from the phone to the voice gateway, but none from the voice gateway to the phones. We also have drops in the output queues that match drops on the asics. I can reset the counters and they will be clear until the call, and then they increment significantly during the call. The voice gateway and phones are non-Cisco. The switch stack has 6 switches. We are trusting the DSCP settings on the phones. All the queue drops from the phones are usually in queues 0-3, but all drops on the voice gateway is in queue 0. Below are the QoS settings; they are mostly default and we have not changed any queuing, thresholds, or buffers. Should we specify larger buffers and threshold for a designated queue and send EF traffic to that queue?
MySwitch#sh mls qos QoS is enabled QoS ip packet dscp rewrite is disabled Typical Port GigabitEthernet1/0/4 trust state: trust dscp
I have a small network using a 24 port 3750 switch. I need to add five computers in another room and only have one Cat 6 cable running there and no room left on the 3750. I got a 3650 to put in the new room with the new computers. The problem is, whenever I plug the new switch into the 3750, it shuts down the port and gives me an err-disable. I can do a shut/no shut and re-enable the port. I searched the web and read about trunking and clusters. I'm not sure which, if either, is appropriate. I see various documentation that shows you can put one switch behind the other. But nothing tells me the configuration which will allow it.
If I have two stackable switches one that connects to the 6509 core switch and the other switch does not, do I have to uplink the switch to the other switch so that switch has route to the core switch or because the switches are daisy chain there is not need to cable one switch to to the other switch connected to core switch?
I am trying to do ios upgrade on 5 stacked 3750 switches. All the switches have different model number, so i am wondering which image file i should download. As far as i understand all the stacked switches should have the same IOS, i may be wrong. The switches have the following model numbers and SW images;
We have several stacks of 3750 switches where this problem is occurring. All of the switches are running IOS version 12.2(50)SE3. (Yes, I know it's old.)
We're seeing inconsistency in how the stack reports members when issuing the following commands:
sow switch show version show inventory
Not all members are showing up in the output of the "show version" and "show inventory" commands. For example:
HUNTI-WV-WDAC03#sh switch H/W Current Switch# Role Mac Address Priority Version State ---------------------------------------------------------- 1 Member 108c.cff2.ea00 15 0 Ready 2 Member 8cb6.4f0a.a600 1 0 Ready *3 Master 8cb6.4f0a.9c00 1 0 Ready (all three switches in stack are displayed)(code)
why the AutoQoS macro does not implement "priority-queue out" when configured on the 3750 platform running certain versions of software. The only other platform I have experience with AutoQos is on the 4500 and it enables priority queuing as expected. So what's up with autoqos on the 3750 on version 12.2(35)SE5?
When it comes to configuring QoS on campus user/phone access ports there are some important settings that can and should be considered but one can argue that enabling the priority queue is the single most impactful or important command. So I was very surprised and concerned when I didn't see priority-queue out. Cisco describes AutoQoS as a simple, quick way of deploying QoS on the LAN and it precludes you from having to learn all of the differences between hardware platforms. But is it true that this tool produces an incomplete config solution? Let me know if I am missing something.
Here is an example of what AutoQoS produces when applied to a 4507 with WS-X4648-RJ45V+E:(other interface commands are left out for simplicity)
interface GigabitEthernet5/25description XYZ switchport mode accessauto qos voip cisco-phoneqos trust device cisco-phoneservice-policy input AutoQos-VoIP-Input-Cos-Policyservice-policy output AutoQos-VoIP-Output-Policy policy-map AutoQos-VoIP-Output-Policy class AutoQos-VoIP-Bearer-QosGroup set dscp ef
[code]......
Here is an example of what AutoQoS produces when applied to a 3750 running version 12.2.(35)SE5: (no priority-queue out)
I am wanting to etherchannel from a 3750 stack to core Layer 3 switches (also 3750) with a cable going to each core switch, I have put both core switches and the stack under a 28bit subnet mask, but I dont seem to be load balancing across both links.
