Assign a VLAN to multiple ports on Cisco 3750?

[BashedRoot]

I have a Cisco 3750G router and generally assign each VLAN to a single port, GigE enabled. I want to assign one particular VLAN to an additional port for optimal, higher speed and traffic flow. I'm also trying to troubleshoot an issue and determine the cause of my problem.

How can I assign a VLAN (VLAN10) to a second, non-consecutive port?

My issue is packets dropping. Only happens on this server and not sure if it's the NIC port, the whole NIC card or not. Below is what a tech told me. Would appreciate some troubleshooting tips on this matter. It's a Dell R610 with an Intel NIC card.

I couldn't help but notice there is a ton of packets being dropped on the second network device which is the same device being used for the backups.

p2p2      Link encap:Ethernet  HWaddr

          inet addr:10.0.0.8  Bcast:10.0.0.255  Mask:255.255.255.0

          inet6 addr: fe80::21b:21ff:fe94:7200/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:7017929664 errors:0 dropped:794049444 overruns:0 frame:0

This usually isn't a good sign. If packets are being dropped during the connection while backups are running I believe it could cause an unknown disconnect since the connection wasn't stable at the time of the transfer.

In my experience this could be happening per one of the following reasons :

-- Network card is going bad

-- Bad cable

-- Bad cable connector

-- Bad switch port

[Francesco Molino]

Hi

I'm not sure to understand your question.

You said you have a Cisco 3750G switch and you want to configure vlan 10 on a specific port, right? If this is not your question, then please explain it again clearly

If so, depending if you want an access or trunk port the commands are:

1. TRUNK

interface g0/x

 switchport encap dot1

 switchport mode trunk

 switchport trunk allow vlan 10

2. ACCESS

interface g0/x

 switchport mode access

 switchport access vlan 10

Concerning your other issue (drops). This kind of issue could lot of things. First I will clear the interface statistics in order to observe really how many drops per 5 minutes you see.

On this particular port, is there only this server or multiple device (switch, blade,...)

[BashedRoot]

Hello,

Thanks for your reply. My post was clear as can be

"How can I assign a VLAN (VLAN10) to a second, non-consecutive port?"

In other words, it's already assigned to one port on the Cisco switch. I want to assign it to a 2nd port as well "for optimal, higher speed and traffic flow"

[Francesco Molino]

Ok yes it was clear and that's why I provide some configuration stuff. It was just to be sure that was what you asked for.

If you just want to connect the server on new port without managing dot1q tag then use access port config. If you are managing dot1q tag on the server, then you need to use trunk port config.

Is this answering your question?

[BashedRoot]

Thanks. I tried what you said, but now it says 'notconnect'? Cable is plugged into the NIC port and switch port. Come to think of it, I think I need to bring up the port (p2p3) on that NIC port on the server in question, which is running Centos 6. However, I'm a bit stuck now. What should that config look like in comparison to the original p2p1 network script?

DEVICE=p2p3
HWADDR=00:1B:21:94:72:03
TYPE=Ethernet
UUID=---
ONBOOT=no
NM_CONTROLLED=yes
BOOTPROTO=dhcp

Cisco3750#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Cisco3750(config)#int Gi2/0/18  
Cisco3750(config-if)# switchport mode access
Cisco3750(config-if)# switchport access vlan 10
Gi2/0/18                     notconnect   10           auto   auto 10/100/1000BaseTX

[Francesco Molino]

ok I assume the port is not in shutdown mode. Could you do a sh interf g2/0/18

does the server has a specific speed/duplex configuration? HAve you tried with a new cable?

[BashedRoot]

Yes cable replaced already.

Cisco3750#sh interf g2/0/18
GigabitEthernet2/0/18 is down, line protocol is down (notconnect) 
  Hardware is Gigabit Ethernet, address is 0012.01db.f612 (bia 0012.01db.f612)
  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, 
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Auto-duplex, Auto-speed, media type is 10/100/1000BaseTX
  input flow-control is off, output flow-control is unsupported 
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

[BashedRoot]

Ok cool, got it connected after running below on Dell box.

/sbin/ifconfig p2p3 up

Now, it's a matter of testing speed using both dual ports simultaneously. Any suggestions please?

[Francesco Molino]

If you want to stress a bit the port, you can use iperf and passing some traffic