Make Fiber Ports Live on Catalyst 3750?

Hello All,
Have 2 Catalyst 3750's connected via fiber to the cisco gbics converts. Both gbic's are plugged into Slot 1 of 4 on the switches. Everything is physically hooked up correctly. My question is what command do I type to make the fiber ports active? I know the fiber led should go orange for 30 sec then green when you plug the fiber cable in the gbic but it's not working because I've got to make that port or interface active first right? Any help would be appreciated. Thanks in advanced!

Double check the cabling. Unplug one of the patch cables from one of the gbics. Look at which connector on the gbic has the light coming out of it. Compare to the fiber patch for which connector has light coming out of it. Ensure you have the fiber plugged into the gbic such that light from one connects to dark on the other. Do this at both ends.
Also, pull the gbics out of the switches & validate both are appropriate for the fiber type you are using. 1000-LX is for single mode fiber; 1000-SX is for multimode fiber.
If you have the interface administratively shut down, this will fix it:
int gig 0/1
no shut

Similar Messages

I cannot connect by console port to Cisco Catalyst 3750 using ethernet to USB.

Hello. I have one Cisco Catalyst 3750 switch, and two 2950 switches. I am trying to reset their settings using a console cable with a trendnet Ethernet to USB adapter. When I try loading hyperterm or putty on com3 there is no signal. I have the communication port setting on com3. I don't know what the old settings are, and they can be reset. I get connectivity lights when plugging the cable into the switch ports. What am I missing?

Are you definitely using the correct COM Port number? On Windows7 Right Click My Computer > Manage Then select Device Manager and expanPorts (COM & LPT)d in my case is shows Prolific USB-to-Serial Comm Port (COM5).
Once you have the right COM Port number just use the default settings in Putty. You may find the COM Port is locked up which will require a reboot.

/31 on Catalyst 3750 routed port

I've discovered the feature 'Using 31-Bit Prefixes on IPv4 Point-to-Point Links' and I'm interested in implementing it on a point-to-point uplink network that terminates on one end to a Catalyst 3750 routed FastEthernet port ("no switchport").
I can enter the IP address in the interface config (172.16.100.0 255.255.255.254), and I get the warning "% Warning: use /31 mask on non point-to-point interface cautiously". Since I can guarantee that this is in fact a point-to-point uplink to a Layer 3 device, can I safely ignore the warning? Is there any way to configure the interface explicitly as a Point-to-Point interface instead of a broadcast interface?
Thanks!
-Mason

Hi,
It doesn't appear the error is platform specific. I am getting the same error in my lab 2600 when configuring a /31 bit mask.
You would use the /31 bit mask only on a p-t-p interface hence, you don't need to tell the interface it's a p-t-p interface. I don't know of any generic command to tell the broadcast interface that it's a p-t-p interface. There is a OSPF command but that doesn't have anything to do with this setup.
R2(config)#int e0/0
R2(config-if)#ip add 1.1.1.0 255.255.255.254
% Warning: use /31 mask on non point-to-point interface cautiously
R2(config-if)#^Z
R2#show run
*Mar 1 18:20:21.795: %SYS-5-CONFIG_I: Configured from console by console int e
/0
Building configuration...
Current configuration : 78 bytes
interface Ethernet0/0
ip address 1.1.1.0 255.255.255.254
half-duplex
end
R2#show ip arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 1.1.1.0 - 0004.dd85.eee0 ARPA Ethernet0/0
R2#ping 1.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/3/4 ms
R2#show ip arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 1.1.1.1 0 0004.dd85.e9c0 ARPA Ethernet0/0
Internet 1.1.1.0 - 0004.dd85.eee0 ARPA Ethernet0/0
HTH
Sundar

Trunking between Huawei S3900 and Cisco catalyst 3750

One of my edge Huawei S3700 switches is dead, I am going to replace it with a Cisco switch Catalyst 3750 series PoE-48 via a trunk link with GE fiber port on both ends, please see the diagram below.
trunk trunk
Core switchrouter<----------S3700<--------------->Cisco Catlyst 3750
I haven’t touch Cisco switch for many years, I would like to ask the following questions:
1.)      Do I need to take any precaution before connecting this Cisco switch into my Huawei network? Only one link between S3700 and C3750, so I don't need worry anout STP? Do I need to worry about Default vlan regarding trunking port?
2.)      I need to use different trucking protocol e.g. 802.1Q etc to interconnect these two switches (S3700-28TP-SI-AC and Catalyst 3750), please see the following configuration:
For C3750:
switchport trunk encapsulation dot1q
switchport trunk native vlan (What you want)
switchport trunk allowed vlan (VLANs required)
switchport mode trunk
spanning-tree portfast trunk
For S3700:
port link-type trunk
port trunk permit vlan all
Do you think the configurations above are right?
Do I need to manually enter Duplex and speed options ?
3.)If the configurations are not right, then what are the commands for trucking port/link should I use on the Cisco switch (it uses IOS software) and Huawei switch? Procedures of the commands would be really helpful !
Any information and help would be much appreciated.
Thanks
Regards

Hello
3750 - basic config
================
See as you are using this switch as an host switch you need to make sure ip routing isn't enabled ( it isn't by default)
Also it looks like the s3700 Huawei switch is permitting all vlans and I assuming the default native vlan is 1 ( as is cisco) so no need to specify the native either.
If you are requiring the access ports on this new cisco 3750 to be in multiple vlans then usually cisco to cisco interconnect would ultise VTP for vlan propagation however this wont occur between the Huawei switch, so you will need to manually add the vlans on the switch also.
so to summarize below is a basic host switch config for 3750.
conf t
no ip routing
hostname XXXXXX
username xxxx privilege 15 secret xxxxxxx
service password-encryption
enable secret xxxxx
security passwords min-length xx
security authentication failure rate xx log
aaa new-model aaa authentication login default local
logging buffered 4096
no service udp-small-servers
no service tcp-small-servers
service timestamps debug datetime msec localtime
service timestamps log datetime msec localtime
no ip domain-lookup
spanning-tree mode rapid-pvst
spanning-tree portfast bpduguard default
int vlan x ( this may or not be vlan 1 - its whatever the L3 vlan interface is on the core switch for management connectivity)
ip address x.x.x.x y.y.y.y.
exit
ip default-gateway x.x.x.x ( ip address of CORE SVI management interface)
vlan x,x,x,x ( add the L2 vlans to the switch as vtp would not be used between the Huawei switch)
exit
int gigx/x
Description Link to Huawei switch
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
no shut
( no need for spanning-tree portfast trunk- this is usually only for ESX host ports)
int rang fa0/1 -48
Description - Access-ports
switchport host
switchport access vlan x (wihout this defaults to vlan 1)
no shut
clock timezone gmt 0
ntp peer
ntp server x.x.x. prefer
res
Paul

Interconnecting Catalyst 3750 and 2948G-L3

I am trying to interconnect a Catalyst 3750 and a 2948G-L3 using fiber GBIC. The interfaces where the GBIC and fiber are attached show up as physically down. I have tried different ports and also changed both switches. No Luck. If I connect a 3524 to the 3750 using the same connection it works.
Are 2948G-L3 switches compatible with the 3750?
Thanks,
VT

Should have no problem. Can you try the following on the 3750's gig interface:
speed nonegotiate
See of the link comes up.
Please rate all posts.

Trying to interconnect Catalyst 3750 with cwdm sfp module

hi,
I try to interconnect 2 Catalyst 3750 switch use cwdm sfp fiber module.
If just plug in, there is no link between 2 switchs.
What's the procedure to make this?
Thanks

you have 2 options with CWDM at the moment. the first option is to use any or all to the 8 wavelenght SFPs: CWDM-SFP-1470= (gray) thru CWDM-SFP-1610= (brown)
with passive multiplexers (MUX) as described here:
http://www.cisco.com/en/US/products/hw/modules/ps5455/products_data_sheet09186a00801a557c.html
or
In the off chance you have only a single strand of fiber available, you would choose:
1000BASE-BX10-D AND 1000BASE-BX10-U SFP FOR SINGLE-FIBER BIDIRECTIONAL APPLICATIONS
as described here:
http://www.cisco.com/en/US/products/hw/modules/ps5455/products_data_sheet0900aecd8033f885.html
Overall, CWDM is a cost effective method of building a Metro-Ethernet LAN / SAN by providing a single pair of single mode fiber the ability to support 8 wavelengths. You can mix and match these wavelengths with 1Gb Ethernet or 2Gb FiberChannel as needed.
rate if helpful
thanks,

Troubleshooting Fiber Connection on a Catalyst 2960

I am trying to test my fiber connectivity on a Catalyst 2960 before I deploy it. So what I thought I would do is connect it to another switch in my office with a open port for the fiber connection. The other switch is a Catalyst 3560G. Here are the port configurations:
interface GigabitEthernet0/2
switchport trunk allowed vlan 1,100
switchport mode trunk
macro description cisco-switch
interface GigabitEthernet0/25
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,100
switchport mode trunk
The first one is the catalyst 2960 and the 3560G is the second.
When you show the interface for each of these it shows that it recognizes the media but the line protocal and the GigbitEthernet Port is down.
Any Ideas?

Sorry... a fiber optic cable with a connector on each end.
To aid in troubleshooting, many times we loopback the signal back to the originating device. An optical loopback is just connecting the transmit (Tx) to the receive (Rx).
The multimode SFP/GBIC transceiver you are using will allow you to directly connect the Transmit and Receive ports without damage to the unit. This should provide you with a green link LED.
If so, then you can reconnect your fibers and loopback (connect the two fibers together) at the far end of the fiber link (use an optical adapter) and see if you get a green LED.

Catalyst (3750 24 10/100/1000T) and (3750 12 SFP) Stacking Problems

Dear all
I'm having a very strange situation here (at least for me)
we have 4 core switches
2 x   WS-C3750G-24T-S Catalyst 3750 24 10/100/1000T + IPB Image
and
2 x   WS-C3750G-12S-S Catalyst 3750 12 SFP + IPB Image
Stack configuration is done this way
when the switches are powered on, the first two SFP core switches are seen as a single stack with the stack master LED turned green on the first switch
the other two (24 10/100/1000T) switches have the RPS LEDs always green, mode cannot be changed, and cannot be accessed by Console connection
but when the (24 10/100/1000T) are powered off, the first (SFP) switch in the stack reports that " Switch 3 and 4 has been removed from Stack "
which means they are stacked but there's something wrong, because
only the SFP ports are shown in the " Show interfaces status " , the ethernet ports of the bottom switches are not present !!!
can you please tell me what's the poblem ?

Dear Daniel
Sorry for my delayed response but i was actually quite busy
but the problem was actually in another sense
the default profile for the Catalyst 3750 SFP is the Aggregate SDM Template
while the 3750 10/100/1000 ethernet Switch Default SDM profile was Desktop profile
so i had an SDM mismatch
DATACENTER#sh switch detail
Switch/Stack Mac Address : 081f.f3cf.1c80
                                           H/W   Current
Switch# Role   Mac Address     Priority Version State
*1       Master 081f.f3cf.1c80     1      0       Ready
2       Member 081f.f3cf.5900     1      0       Ready
3       Member aca0.16ac.0180     1      2       SDM Mismatch
4       Member aca0.16a3.bc80     1      2       SDM Mismatch
         Stack Port Status             Neighbors
Switch# Port 1     Port 2           Port 1   Port 2
1        Ok         Ok                2        4
2        Ok         Ok                3        1
3        Ok         Ok                4        2
4        Ok         Ok                1        3
all i did was changing the default profile of the SFP switches into the Desktop Profile and problem was solved
switch 1 provision ws-c3750g-12s
switch 2 provision ws-c3750g-12s
switch 3 provision ws-c3750g-24t
switch 4 provision ws-c3750g-24t
system mtu routing 1500
ip subnet-zero
no file verify auto
spanning-tree mode pvst
spanning-tree extend system-id
vlan internal allocation policy ascending
interface GigabitEthernet1/0/1
interface GigabitEthernet1/0/2
interface GigabitEthernet1/0/3
interface GigabitEthernet1/0/4
interface GigabitEthernet1/0/5
interface GigabitEthernet1/0/6
interface GigabitEthernet1/0/7
interface GigabitEthernet1/0/8
interface GigabitEthernet1/0/9
interface GigabitEthernet1/0/10
interface GigabitEthernet1/0/11
interface GigabitEthernet1/0/12
interface GigabitEthernet2/0/1
interface GigabitEthernet2/0/2
interface GigabitEthernet2/0/3
switchport trunk encapsulation dot1q
switchport mode trunk
interface GigabitEthernet2/0/4
interface GigabitEthernet2/0/5
interface GigabitEthernet2/0/6
interface GigabitEthernet2/0/7
interface GigabitEthernet2/0/8
interface GigabitEthernet2/0/9
interface GigabitEthernet2/0/10
interface GigabitEthernet2/0/11
interface GigabitEthernet2/0/12
interface GigabitEthernet3/0/1
interface GigabitEthernet3/0/2
interface GigabitEthernet3/0/3
interface GigabitEthernet3/0/4
interface GigabitEthernet3/0/5
interface GigabitEthernet3/0/6
interface GigabitEthernet3/0/7
interface GigabitEthernet3/0/8
interface GigabitEthernet3/0/9
interface GigabitEthernet3/0/10
interface GigabitEthernet3/0/11
interface GigabitEthernet3/0/12
interface GigabitEthernet3/0/13
interface GigabitEthernet3/0/14
interface GigabitEthernet3/0/15
interface GigabitEthernet3/0/16
interface GigabitEthernet3/0/17
interface GigabitEthernet3/0/18
interface GigabitEthernet3/0/19
interface GigabitEthernet3/0/20
interface GigabitEthernet3/0/21
interface GigabitEthernet3/0/22
interface GigabitEthernet3/0/23
interface GigabitEthernet3/0/24
interface GigabitEthernet4/0/1
interface GigabitEthernet4/0/2
interface GigabitEthernet4/0/3
interface GigabitEthernet4/0/4
interface GigabitEthernet4/0/5
interface GigabitEthernet4/0/6
interface GigabitEthernet4/0/7
interface GigabitEthernet4/0/8
interface GigabitEthernet4/0/9
interface GigabitEthernet4/0/10
interface GigabitEthernet4/0/11
interface GigabitEthernet4/0/12
interface GigabitEthernet4/0/13
interface GigabitEthernet4/0/14
interface GigabitEthernet4/0/15
interface GigabitEthernet4/0/16
interface GigabitEthernet4/0/17
interface GigabitEthernet4/0/18
interface GigabitEthernet4/0/19
interface GigabitEthernet4/0/20
interface GigabitEthernet4/0/21
interface GigabitEthernet4/0/22
interface GigabitEthernet4/0/23
interface GigabitEthernet4/0/24
that's it !
: D
cheers

Debian Linux Bonding and Cisco Catalyst 3750 - best practise?

Hello everybody,
I would like to know what's best practice to do this:
The two NICs of a Debian Linux server wants to be connected with two Switchports of a Cisco Catalyst 3750 switch(stack). My goal is to have load-balancing and failover.
My /etc/network/interfaces looks like this:
iface bond0 inet static
       address 192.168.0.30
       netmask 255.255.255.0
       network 192.168.0.0
       broadcast 192.168.0.255
       gateway 192.168.0.1
       dns-nameservers 192.168.0.10 192.168.0.20
       dns-search xyz.mycompany.com
       slaves eth0 eth1
       bond_mode ???
       bond_miimon 100
       bond_downdelay 200
       bond-updelay 200
First question: What bond mode should I use?
The switchports looks like this:
interface GigabitEthernet3/0/4
switchport access vlan 20
switchport mode access
spanning-tree portfast
What changes are necessery here? Something like this?
interface GigabitEthernet3/0/4
switchport trunk encapsulation dot1q
switchport mode trunk
spanning-tree portfast
Thanks a lot for suggestions, hints, etc.! :-)
Greets
Stephan

Hi Michael,
thanks a lot for your answer - and sorry for my late reply!
I like to show you my solution - I hope that it is a solution. ;-)
My config on the switch(stack):
switch#show etherchannel summary
Group Port-channel Protocol    Ports
------+-------------+-----------+-----------------------------------------------
2      Po2(SU)         LACP      Gi3/0/3(P) Gi4/0/3(P)
switch#show running-config interface GigabitEthernet 3/0/3
Building configuration...
Current configuration : 172 bytes
interface GigabitEthernet3/0/3
description myserver, eth0
switchport access vlan 20
switchport mode access
channel-group 2 mode active
spanning-tree portfast
end
lansw01#show running-config interface GigabitEthernet 4/0/3
Building configuration...
Current configuration : 172 bytes
interface GigabitEthernet4/0/3
description myserver, eth1
switchport access vlan 20
switchport mode access
channel-group 2 mode active
spanning-tree portfast
end
switch#show running-config interface port-channel 2
Building configuration...
Current configuration : 82 bytes
interface Port-channel2
switchport access vlan 20
switchport mode access
end
The /etc/network/interfaces of my Debian machine looks like this:
auto lo
iface lo inet loopback
auto bond0
        iface bond0 inet static
        address 192.168.1.xxx
        netmask 255.255.255.0
        gateway 192.168.1.xxx
        dns-nameservers 192.168.1.xxx
        dns-search xxx.xxx.xxx
        bond-mode 4
        bond-miimon 100
        bond-downdelay 200
        bond-updelay 200
        bond-lacp-rate 1
        slaves eth0 eth1
This setup seems to work well. But I'm wondering that there is nothing with "trunking" in my setup. Would you like to give me your opinion about this?
Thanks a lot and many greets
Stephan

Catalyst 3750 Switch

How many total Vlans can you create in Catalyst 3750 Switch ? I read a document about Catalyst 3750 Switch. This document is said that "Although the switch stack supports a total of 1005 (normal-range and extended-range) VLANs, the
number of routed ports". However, I am not sure. Can you confirm for me ? Thanks

this link should be of some help to answer your question.
http://www.cisco.com/en/US/products/hw/switches/ps5532/products_command_reference_chapter09186a00803ec324.html#wp1031710
HTH-Cheers,
Swaroop

Aggregating multiple fiber ports on MDS directors

Hi All,
Going forward our new servers will have the capability of aggregating multiple fiber ports into fewer connections on the SAN switch. I am told that there is a particular setting that needs to be enable on the switch for this functionality to work, kindly let me know more details on this?
What we intend is to reduce the port usage on Cisco MDS9509 like in map in many hba's to few physical ports instead of one to one?
regards,
Samir

Switch-Server port channeling feature was added in MDS NX-OS 4.1(3). Make sure your MDS at least runs that release.
http://www.cisco.com/en/US/docs/switches/datacenter/mds9000/sw/4_1/configuration/guides/cli_4_1/pc.html#wp1291942
http://www.cisco.com/en/US/docs/switches/datacenter/mds9000/sw/4_1/configuration/guides/cli_4_1/pc.html#wp1209658
Regards,
Roman

System FCS error frames on Catalyst 3750

Please,
may someone explain what are the "System FCS error frames" I see with "show controllers ethernet-controller" on some ports of a Catalyst (on trunk and also on access ports) WS-C3750G-24TS-S (3 switches in stackwyse)?
Error counters advance slowly, but they do grow... and I am afraid this could be the reason for variable slow access time to a server application menu...
For example "8 System FCS error frames".
The ports are connected to a PIX-515E and I see the same error count on the firewall interfaces (PIX "show interface" command shows me "8 input errors, 8 CRC, 0 frame, 0 overrun, 8 ignored, 0 abort")
A few errors may be seen also on other ports, connected to other (C3550)switches.
I tried to upgrade the IOS version, so I loaded "ipbase 12.2(25)SEB4 " on the Catalyst 3750, but it did not solve the problem.
PIX firewalls are running software 6.3(4).
Why these errors are called "System FCS error frames" ? I could not find anything searching on Cisco CCO!
Thanks

I apologies for the delay answering, my notebook has been down for 5 days and also cco access password...
Thank you for the explanation and suggestion.
We have a second rack with another three switch 4750 in stackwyse, same models as the "faulty" ones, and the errors are not present on those switches, so it must be something hardware related on the first group of switches.
I cannot touch those devices at the moment, we captured traffic frames with 3 Notebook PCs running "Ethereral" lan sniffer, traffic to and from the server and two clients and we discovered that in different ports of those switches, some packets never reach the clients, causing many TCP retransmissions, especially witch continuous traffic (http get and ftp transfers). This problem is visible on some, but not all, of the catalsyt 3750 switches in stackwyse, but in every one of the three switches. We are planning to go on-site and replace the hopefully faulty one ( or reseat the cables as you suggested).
Is this a problem you have seen before?
Regards
Franco Feri

Catalyst 3750 interface explaination

Dear Sir,
I don't understand as follows :-
1.) why on Catalyst3750 interface fastethernet 1/0/1 ?? <--- what's the meaning of 1/0/1 ?
2.) what's the meaning of no mdix auto?
Please explain and advise.
Thank you.

The 3750 has many interesting features, I recommaned you go through before you connect your switches in a production environment.
Basically, you should provision your stack master with the number of switches and their types. You could provision as well the interfaces with their corresponding configurations, even though the other elements are still not connected yet. This way, you ensure, when you add a provisioned element with the right number, it will take exactly the provisioned configuration you've already set on the master,... as well when changing an element with an other, when moving it,... you will have just to provision its number and then connect it to the stack while is not yet powered on.
Second, it is recommanded to set priority to each element, this way you will have a deterministic configuration and you know in advance which one will be reelected as master in any sitution.
If no provision is set on the stack master, when you connect a switch, it has by default the number "1", in this case the newly added switch will take the lowest switch number available (2).
1.) 1/0/1 --> so the second will be 2/0/1.
And to address its ports you tape: 2/0/1, 2/0/2, 2/0/3,2/0/4,...2/0/24,...
How to stacked both of the catalyst 3750? just purchase one stackable cable to link both of them and will it automatically configure the 2nd switch from 1/0/1 to 2/0/1 after we plug in the stackable cable into the 2nd switch.
For large deployment I recommand the switches to be provisioned manually: Before stacking the switches:
1/ power on the switch that will be the stack master, then wait till it will be in "Ready" state by issuing "show switch detail" command.
2/ Provision the stack master with the desired stack configuration (numbers of switches, types of switches and interfaces configurations).
3/ Reload the stack master.
4/ Provision the second switch with its number and type.
5/ Power off the second switch afetr having saved its configuration.
6/ Stack the second switch to the stack master.
7/ power it on. It will take the provisioned configuration on the stack master.
The advantage of this procedure is that switches could not be renumbered while stacked and running.
Repeat steps 4 to 7 for each new element having been provisioned in the stack master.
Do not forget to save after each step.
2.) so i put "no mdix auto" on catalyst 3750, what's the meaning and impact?
no mdix-auto will disable the advanced feature of abstructing the type of cable (staight throu or cross over). You will downgrade to the standard interfaces specifications. In fact, mdix-auto (activated by default) permits to not to have the "overhead" of distinguishing crossover and straight throu cables, the interfaces will adapt automatically to the type of cable.
An other advantage of this function is that it opimises (combined with other functions) error and recovery procedures in layers 1 and 2.
Mohamed BEN HASSINE

Configuring a Catalyst 3750

I want to configure a route between Port1 and Port2 and another route between Port3 and Port4 of the catalyst 3750. Is that possible and how can I do this?

Configure the ports to be layer 3 just like any other router. But, you might be better off creating SVI or interface vlan and assign the ports to accordingly to the SVI and just enable ip routing which should be enabled by default.

Configuring dual-links on catalyst 3750

I've dual-links (laser and Fiber optic media) to connect my office and colocation. both of using catalyst 3750, there are also 4 VLAN. the problem are Fiber optic provider only allow 1 VLAN to connect my network to colocation, when the Laser drop, Fiber optic can't send traffic to colocation.
is there any clue for this problem...?
thanks,

Hey,
Please give the Show config output from both the switches. Would like to see the config on both the ends.
regards,
-amit singh

Make Fiber Ports Live on Catalyst 3750?

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