Switches / Hubs

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A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

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Good evening ladies and gents,

I am currently trying to up link a Nexus  3172TQ to an existing and live production 3850e stack.

The aim, and requirement is to have 4x 10GB ports (on one switch) on the 3850 stack to one 40GB port on the Nexus 3172TQ.

I am using a compatible QSFP-4SFP10G-CU1M cable, but not too sure if the config required on the interfaces on each switch.

I have attempted just the cable, with just trunks. I also attempted to create a port-channel with the idea of 40GB throughput to 40GB throughput.. however i only get link lights on the 3850 and nothing on the Nexus . I get a "link state" down on the Nexus, but admin interface is up.

It doesn't seem to see the cable on the nexus, and i just cant figure out why. Is there a certain config for these cables?

Thank you, please let me know if you require anymore info.
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This is using a Netgear Prosaft M4100-50G L2 switch. There are 2 VLANs on this switch, namely, vlan 10 besides 1. Ports 12, 21-35, 38-40, and 44 are on vlan 10. The rest is vlan 1. This switch is located in our remote office. There are 2 uplinks connected to this switch from our hq. The first uplink, connected to port 43, is basically uplink for vlan 1; second uplink, connected to port 24, is means for vlan 10. This logical segregation works perfectly, any port either belong to vlan 1 or 10, can grab the IP from respective dhcp servers located in hq.

2 week ago, thing changed. Users using vlan 1 ports found that they no more able to grab the IP. Their port looks like is entirely "isolated". After much checking, we were having a "workaround", that is, get in an additional 8-port switch, move the first uplink, and connect it to this 8-port switch. After that, get an additional short network cable, with one end connect to 8-port switch, and the other end to any vlan 1 port of this netgear switch. The vlan 1 operations are back to normal.

Just wondering why? How to get the netgear switch to work alone without this workaround?
Please see the netgear config as attached.

Thanks in advance.
EE---Netgear-M4100-50G-Prosaft-Switc.txt
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Dear Experts,

I recently ran into some issues with my new Switching equipment. Since cost is always a big factor in home lab toying I changed from HP ProCurve to the Ubiquiti EdgeSwitch. More specific I change my 2920-24G with a 2SFP+ and a 2 10GBe extension to a Ubiquiti ES-48 and a Ubiquiti ES-16-XG.

Since I have now more than enough SFP+ Ports for my home lab toying around I wanted to create LACP between the Node (ESX Host) and the Ubiquiti ES-16-XG to connect the node with maximum performance to the Synology DS3615xs which I also upgraded with a dual Port SFP+ Card.

Here a little schema
lacp_issue.PNG
Now the Synology DS3615xs was very easy to setup and as you can see in the attached picture (SynologyLACP.png) seams to be working as a dynamic lacp member on the ES-16-XG.

With the vSphere 6.5 Distributed Switch it seams like a whole other story... I can't seam to find the ressources or manuals where they describe how to do it with the DS or how to get it working.

Can someone point me in the right direction?

Thanks in advance

Cheers,
Yves
SynologyLACP.PNG
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Cam you tell me the ARP table capacity of an HP/Aruba 2920 - 24port (not POE) switch?  I can't seem find the info in any documentation and I have had no luck getting in touch of a tech with HP.
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Dear Experts,

My colleague somehow remove / deleted the HP switch files.

When I turn it on, it displays this?

System is starting...
Press Ctrl+D to access BASIC-BOOTWARE MENU
Booting Normal Extend BootWare
The Extend BootWare is self-decompressing......................Done!

****************************************************************************
*                                                                          *
*            HPE 1920-8G Switch JG920A BootWare, Version 1.17              *
*                                                                          *
****************************************************************************
Copyright (c) 2010-2016 Hewlett Packard Enterprise Development LP

Compiled Date       : Jan 18 2016 09:58:32
CPU Type            : MIPS4kec
CPU L1 Cache        : 16KB
CPU Clock Speed     : 500MHz
Memory Type         : DDR3 SDRAM
Memory Size         : 128MB
Memory Speed        : 300MHz
BootWare Size       : 3MB
Flash Size          : 32MB


BootWare Validating...
Application program does not exist.
BootWare password: Not required. Please press Enter to continue.


How can I resolve this?
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I have cisco 3650 and 3560G connected one to one port as trunk. Ports are gig1/1/1 to g0/1

What is the recommended etherchannel configuration from port gig1/1/1, gig 1/1/2 to g0/1, g0/2?
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First, If I am correct:
Standard Access-list  can match traffic based on Source IP address only
Extended Access-list can match traffic based on Source/Destination IP address , port number, protocol, etc...

well, there is also  Named Access-list. We can have Standard Named Access-list and Extended Named Access-list
  Is Standard Named Access-list similar to Standard Access-list, it can match traffic based on Source IP address only ?
Is Extended Named Access-list  similar to Extended  Access-list ,it can match traffic based on Source/Destination IP address , port number, protocol, etc. ?

Thank you
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I am remodeling four homes.  I have  installed eight port structured wiring systems in all four.  Each wall jack (room) includes one ethernet jack, one cable jack, and one phone jack.  Everything is homerun to the utility room in the basement. Within the wiring cabinet located there, are punch down blocks and patch panels for all wires and cables. I would like to install  in each cabinet, an eight port router or switch to include an integrated DHCP server, and POE  jacks. One of these Jack's will be wired to a ceiling mounted Wi-Fi access point on the third floor in the center of the home. This device should be dual band AC 1200  or greater. Ultimately, the router or switch will be plugged into a cable modem providing Internet and telephone service. I am having trouble finding the router or switch, which needs to be small enough  to fit inside the wiring panel.  I also need an inexpensive access point device.  The cable modem will be mounted by the cable service provider outside the panel.  This arrangement will allow plug-and-play of any wired or wireless device in the home without the need for a PC  based DHCP server arrangement. Has anyone done this? Any recommendations? I need to keep this reasonably inexpensive.
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We have been asked to connect a 200Mbps fibre connection (expandable to 1Gb) to 10 independent business units in a small business park. The fibre provider will put a Cisco 1921 router on the end. They have no interest in managing the ongoing connections to the individual business units. That's down to us. Someone recommended a Cisco SG500 switch to add to this to satisfy the requirements:

1. control of bandwidth to each unit so they each get what they have asked for (and paid for) and no more
2. separate public IP assigned to each business unit (one each)
3. each unit can only access internet and not each other's networks

This is a little outside my day-to-day networking experience so rather than fumble my way forward, any pointers, issues to watch out for would be much appreciated.

Thanks,  Andy.
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Does anyone know why the switch slows down so much that the VOIP starts to have Jitter and after a reboot it works fine for a week again. The switch runs the PC's through the Phones. There are no VLAN's programmed at the moment. The switch is stock standard. Are there any settings I can change?
0
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Hello all,



I'm having problems pinging from my data subnet (192.168.0.0/24) to my voice subnet (10.10.10.0/24). data subnet is connected to 0/1 and voice subnet to 0/2 on my ASA5510. I've tried adding static routes on each of the switches and enabled ip routing as well. Voice Switch has VLAN1 with ip 10.10.10.2 with 10.10.10.1 being the IP on 0/2 on ASA.  Likewise Data Switch has VLAN1 with ip 192.168.0.2 and interface 0/1 on ASA has 192.168.0.1.



Can someone please point me in the right direction?



Thank you!
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I have an Engenius EAP600 which I have configured only for Guest Wifi. I wanted to separate the clients that connect to that AP to only allow internet access and block any kind of local network access. The AP is connected to a Layer3 Cisco Switch which then connects to an ASA-5505 firewall. I'm a little rusty on VLAN could someone help with the commands for the Switch and the ASA to set this up?
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Which VLAN   to enable ARP inspection

I would like to know which VLAN to enable ARP Inspection. Is it going to be on the same VLAN where the Trusted DHCP server resides on ?
Or on every VLAN in the network ?

Switch(config)#ip arp inspection vlan <VLAN Name>



I also wants to know about the DHCP Option 82 configuration.
Using IP helper-address <IP address> is enough or  we need to add:
ip dhcp relay information option

Thank you
0
Hi, does anyone know any weakness of Cisco devices (router, switch, Firewall)? Is there any way/tool to assess their vulnerabilities?
0
Hi All,

I'd like to get the config file off both these makes of cisco equipment does anyone know the proper command config to do so/

thank you for your help
0
If I am correct, BPDU Guard on all switch ports , protects the switch from a loop. If a user plugs in another switch to a port, it will go into err-disable state.


Switch-port port-security violation , will achieve the same purpose in that regard.

the only difference I see is  Switch-port port-security violation has other option such as, Protect, Restrict, Shutdown.

I would like to know form Network Experts, which command is mostly used in switches access ports to prevent rogue switch from being introduced to the network ?

Thank you
0
I am planning to upgrade the firmware of catalyst 2960
I checked the version I saw below

Switch#sho ver
Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.0(2a)EX5, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2015 by Cisco Systems, Inc.
Compiled Mon 16-Feb-15 08:16 by prod_rel_team
ROM: Bootstrap program is C2960X boot loader
BOOTLDR: C2960X Boot Loader (C2960X-HBOOT-M) Version 15.2(3r)E1, RELEASE SOFTWARE (fc1)
Switch uptime is 46 weeks, 2 days, 1 hour, 0 minutes
System returned to ROM by power-on
System restarted at 07:50:33 UTC Fri Jul 22 2016
System image file is "flash:/c2960x-universalk9-mz.150-2a.EX5/c2960x-universalk9-mz.150-2a.EX5.bin"

I downloaded below files and I have TFTP server ready to upload the files.
c2960x-universalk9-mz.152-5b.E.bin
c2960x-universalk9-tar.152-5b.E.tar

How to upgrade to 152.5?
Your help is appreciated
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Hi All,

I'm currently looking at this proposal & thinking of implementing OSPF & MLPS I'd like some support with the config & any ideas of best practices?

Thank you all.
ospf.PNG
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Hi, the title said it all. Can anyone draft me some pros and cons of stacking switches?

And is it possible to simulate this techniques in GNS3, Packet Tracer or something else?
0
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Assuming I have 2 switches connecting to each other.
on one switch I configure  Port-channel Load-balance src-mac
and on the other switch I configure Port-channel Load-balance dst-mac

I have not tried yet it, but wonder if it will work

Thank you
0
I have a security camera project that requires a run of about 1000FT for a few cameras.

I know Cat5/6 are not options due to the 300ft limitation.  I guess I could use POE switches at 300/600/900 ft as repeaters but that doesn't sound like a viable solution.

any ideas?
0
Hi All,

I am putting a solution together.  A supplier has quoted 2x Cisco Catalyst 3850 with a 8x10G Fibre Module. These switches seem to be very OTT for a small 3 host vSan deployment and have quoted around 30k for the pair.

Are they any other recommended switches which are way cheaper than the above. I require only 8 SFP+ ports per switch.

Thank in advance.
0
Hi,

My apologies if I'm unable to put the question right, I am a beginner and would not understand why Im not able to log into the redundant device. These are Cisco WS-6509-E running the WS-SUP720-3B

I am trying to do an IOS upgrade on 2 devices

Device A

Device B (Redundant to Device A)

These are Access level switches and Im using SecureCRT to log into the devices. I am successfully able to log in the Device A and back up the configs. However when trying to log in to Device B - it gives me the below error

ssh: connect to host xx.xxx.z.15 port 22: Connection refused

IP of device A is xx.xxx.z.14.

What can be done in this case? Thanks in Advance !
0
Here is my router's configurations (with fake public IP addresses;-)

interface GigabitEthernet0/0
 ip address 113.160.61.14 255.255.255.252

 ip nat outside
 ip virtual-reassembly
 duplex auto
 speed auto

interface GigabitEthernet0/1
 ip address 101.96.10.141 255.255.255.192

 ip nat outside
 ip virtual-reassembly
 duplex auto
 speed auto
 
interface GigabitEthernet0/2
 ip address 172.16.2.28 255.255.255.248
 ip flow ingress
 ip nat inside
 ip virtual-reassembly
 duplex auto
 speed auto

ip nat inside source list ftth interface GigabitEthernet0/0 overload

ip route 0.0.0.0 0.0.0.0 113.160.61.13 100
ip route 0.0.0.0 0.0.0.0 101.96.10.129 200


ip access-list extended ftth
 permit ip 192.168.7.0 0.0.0.255 any
 permit ip 192.168.1.0 0.0.0.255 any
 permit ip 192.168.8.0 0.0.0.255 any
 permit ip 192.168.9.0 0.0.0.255 any

This is a result from "show ip int b"
Interface                            IP-Address         OK?     Method Status            Protocol
GigabitEthernet0/0         113.160.61.14    YES        NVRAM  up                    up
GigabitEthernet0/1         101.96.10.141  YES        manual up                    up
NVI0                          113.160.61.14    YES         unset  up                    up

==================================================================

So as you can see we have 2 WAN interfaces to 2 different ISPs, we change some configurations and saw …
0
Hi guys, is there an software/environment which can simulate HP Aruba Switch/router? Or can we simulate it on GNS3? If so, does anyone got any link of ISO/IMAGE file?
0

Switches / Hubs

20K

Solutions

6

Articles & Videos

17K

Contributors

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.