Cisco Switching/Routing :: 3750x How Does A Switch Choose Its Default Source Interface
Oct 31, 2012
i have a stack of 3750x, with minimal configuration. there are two vlans, and two vlan interfaces with IP addresses. when i ping out from this switch to another host, it picks vlan1's ip address as the source automatically. i tested this by doing two pings with extended options using each vlan's interface as the source, and got different results. how the switch decided to use the first vlan's ip address as a source.
I am looking for a way to bind between a switch interface (cat 3750X) and a DHCP server reply.The switch can operate as the DHCP server .a PC connected to interface Gi 1/0/1 will lways get IP address 10.0.0.1 because it is connected to interface Gi 1/0/1, a PC connected to interface Gi 1/0/5 will lways get IP address 10.0.0.5 because it is connected to interface Gi 1/0/5 and so on... (no matter the source MAC address who sends the DHCP request).
I've got a 3750X, IOS 15.0 IP Base license, reset to factory defaults, and I want to use the FastEthernet0 out-of-band management port on the backside next to the console port. The idea is that this port should provide a management interface that does not participate in the routing table. Problem is, contrary to the documentation, that configuring an IP address on the interface does make it show up in 'show ip route'. So it's still part of the routing table. Also, I'm unable to find the commands to change this and set a default gateway for just the management interface. I'm pretty sure this has to be possible, I remember seeing something similar on an ASA once. The 3750 configuration guide on Cisco.com does not seem to mention it.I considered using VRF but it's an IP Base license, no VRF.
I have configured the ip telnet source-interface Loopback 0 command on a Nexus7010, but when I telnet to another device and do a show users, the ip address is of the closest interface to the device I telnet to, not the ip address of the Loopback. All interfaces are in vrf default. I am running 5.1(6) NXOS.
is it possible, to use a Catalyst Switch (in my case a 3560E) as a source for a console session to another Catalyst? In principle to use it as a console terminal server.
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.
we're having an issue with the command "cts dot1x" when applied to an uplink interface. It basically kils the connection with this command is applied. Once you remove it, everything is back to normal, the platform is a cisco 3750x.
We have a remote site that is using 3750X switches as layer 2 switches back to our home site. The uplink port is showing dropped packets but the utilization on the link is never about 10%. We have a 100Mb circuit to this site. Our speed tests and iperf tests are not showing any issues that we can see. However the port is still droping packets. It is not dropping at a high rate but they are dropping.
I am in the process of installing a 3750x (IOS 12.2 (53r) SE2 IP Base) Cisco Catalyst switch in a new network of just 2 PC's (2 hosts, OS windows7 64Bits). I have enabled SVI interfaces with the both hosts installed in 2 different network segments. We then start connectivity test. The response time for the PING command between both hosts remain below 1 millisecond, whereas the response time between the hosts and their correspondent SVI interface is variable, and at all time is higher than 1 millisecond, sometimes it reaches 17 milliseconds. (Note that the switch CPU usage is only 8% at the time of testing) We have performed this same connectivity test changing the 3750x switches and in two different locations obtaining the same results.
It seems I have seen this before (and even done it once a few years ago).. but it has been a while. I have a stack with a Cisco 3750 stack that I have to replace a member.The replacement switch is a 3750X.
I think I have to upgrade the IOS of the older switch to be the same as the 3750X.
Current switch: WS-C3750G-48TS 12.2(46)SE TO BE ADDED WS-c3570X-48 15.0 (1)SE2
It seems to me there was a way to upgrade the older switch IOS from the newer switch or downgrade the newer switch with the older IOS.I dont have the Cisco account to download updated IOSs.
my company pay a switch 3750 X. WS-C3750X-24T-E. It uses IP services basically but I failed to configure InterVLAN routing. why interVLAN routing doesn't work on my switch?
when enabling multicasting on layer 3 interfaces the CPU becomes fully utilized , is there any specific configuration should be enabled to reduce this .
Config :
Inetface vlan 100 ip pim sparse-dense ip igmp version 3
I have a 3750X 24 port switch (with NM-1G network module) running IOS 15.0(1). Is there any benefit or reason to plug in the included Stack Wise cable and loop it back to itself in a single switch installation?
I don't see any recommendation in the documentation. The data sheet indicates a single switch is a non-blocking device so I'd think there's no bandwidth advantage like there is when connecting an actual multi-switch stack and needing to close the loop for the full 32 Gbps stack bandwidth.
About an hour ago I had the master switch on one of my 3750x (WS-C3750X-48PF-S) stacks crash. The only two items we've found that could have caused this issue are the roughly 1.3 million big buffer misses and several of the following in the syslog
SLT:WARN:No exporter configured for smartlog! I do not have smartlogging turned on, nor is there a netflow exporter configured
sh logging smartlogsmartlog is disabledsmartlog exporter:smartlog pkt length: 64 Total pkts processed: 0Total DHCP Snooping pkts processed: 0Total DAI pkts processed: 0Total IPSG pkts processed: 0Total ACL pkts processed: 0
I did not see any traffic spikes prior to the crash.
This stack has been stable since it's last IOS upgrade from 12.2(58)SE1 to 12.2(58)SE2 back in October 2011 so this has me a little worried.
Cannot set route map on interface vlan. which in non default vrf on Cisco 3750.IOS c3750-ipservicesk9-mz.122-55.SE.bin sdm prefer route in enable ip vrf users rd 200:0 route-target export 200:0 route-target import 200:0 interface Vlan201 description Users 1 ip vrf forwarding users ip address 10.31.76.1 255.255.252.0 ip helper-address 10.31.4.57 route-map fromuser permit 10 match ip address fromuser set ip next-hop 10.31.128.155 When I enter "ip policy route-map fromuser" to interface Vlan 201 I heve the message:
% Remove VRF configuration from interface Vlan201 first
when will be the command "default interface x/x" on the Nexus 5000 platform available? Even with latest software version (5.1.3.N2.1a) it is not possible. For Nexus7000 it's working fine with 5.2 train.Is there a feature request for it? If not here it is!!It's horrible to deconfigure many interfaces especially in N5k environments with many FEXes.
I've 3750X switch that isn't loading email. then I went to rommon mode and accidently for "format flash". after that I loaded 15.0 SE2 s/w on it using tftp server but it doesn't boot up with that image. flash had only .bin file after I loaded it from tftp server.
since it wasn't booting up, I did format flash again and thought to load image again from tftp server but now, it doesn't load image from tftp server.
I have a 3750X four-switch stack acting as the core of a fairly simple LAN. All I need to achieve (and this seems inordinately hard, but it is entirely likely that I'm just being dense) is to get access to the internet through my core switch, through the firewall and out through my VSAT. I've spoken at some length with the firewall providers (Cyberoam) and they tell me all I need to do when I migrate onto my new system (Cyberoam is currently in place at the entrance to our existing LAN) is change the local IP address of the Firewall, plug in the new switch to the LAN port, and away I go. Tried that, didn't work, so obviously I'm missing something.
i am seeing very high utilization on a random basis on the stack. and the logs indicate me that there is a pattern where there is a stack power cable shows inserted (which was never unplugged) followed by sudden spike in the utilization.
001018: *Mar 6 16:21:22.138: %PLATFORM_STACKPOWER-6-CABLE_EVENT: Switch 4 stack power cable 1 inserted 001019: *Mar 6 18:18:37.982: %SYS-1-CPURISINGTHRESHOLD: Threshold: Total CPU
I work at a hospital and we have 3750X-48P switches in stacks in various locations throughout the hospital. We have noticed that when an EKG machine is plugged into one of the ports on some of these switches and the EKG machines are set manually to 100/Full, the ports are no longer usable until the switch is restarted. The switch is configured for auto. If the EKG machine is set to auto, it will work and not cause problems. The link on the interface will show up/up and there will be output packets increasing. However, there will be no inputs on the link and the port is unusable. Unfortunately, even when the device is removed, the port becomes unusable for any device. Is there any way to fix this problem without rebooting the switch?
In change network topology, we are going to assign PC's Gateway as Switch (3750X) IP Address rather than server IP Address. Currently we have configured all Sytems's Gateway is Internet Server IP Address which we are going to replace with Switch IP as Gateway.Issue is while connecting specific application like team viewer in which application tried to send keepalive message to the live server and in case of switch/router IP as gateway. Connection doesn't established. However it is working fine when Internet Server IP treated as gateway.
We have a 3750X VTP Server and the rest of the switches are clients.
Due to cabling issues, we have a switch (Switch F) that we can't connect directly to the 3750X so we have it connected through another switch. Everything is set to VTP client with the correct domain and password but this not-directly-connected switch isn't receiving any VTP VLANs.
Anything I need to do on Switch D so that Switch F can receive the VTP updates?
I have a LIII Switch Cisco 3750x ,with diffrent Vlans , Some users are in Vlan 102 (10.10.2.0) and Some Users are in Vlan1 (10.10.1.0) , now i want to restrict the Vlan102 users to access Vlan1 , i am pasting my configuration below , how to create a access list .
interface Vlan1 ip address 10.10.1.36 255.255.255.0 ip helper-address 10.10.1.36
In my environment we have 3750x switches running ios 15.0 (1) SE2. We have port security mac address sticky configured on all our switch ports. I noticed that we have several interfaces (on different switches) that are up but have not captured the MAC address from the workstation. Here is one example:
I want to limit the bandwidth going to remote site on the switch connecting to our netapp.We have a 4 port channel group setup on our 3750x switch going to our netapp storage. We have a Wan 100mb link to our remote site and we want only 60MBs of that link to be used for Netapp traffic all other local traffic needs to use the full amount of the bandwidth to the netapp.
Is possible to allocate bandwidth in this way and how would I go about this? We dont have access to the routers for the link and they plug directly into a port on our cisco.
