a device that bridges network segments, operating at the OSI link layer level.

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11 views

Cisco 6500 - spike of DHCP_SNOOPING-4-QUEUE_FULL causing clients to lose connectivity

Today we had an incident that started with people complaining they couldn't connect to our wifi after coming back from lunch. Long story short, clients were no longer able to get IP addresses from ...
0
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2answers
21 views

cisco 3850 in separate wiring closets - VSS?

I have two new 3850 24 port gig switches. I am putting one in the front wiring closet of our warehouse, the other in the rear. IS there a way to have these be a layer 2 / layer 3 Virtual Switch using ...
-4
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1answer
28 views

Who sends broadcast message? [on hold]

Are hosts like PCs only one that send broadcast messages? I know that switches just send them further, and routers reject them.
9
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4answers
4k views

How long do managed gigabit ethernet switches take to boot up?

One critical drawback that I have found in researching managed-switches, and one that I have some past experience with is that anything with "lots" of firmware is going to have lots of issues ...
0
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0answers
5 views

Querying counters and interface name from cisco router is getting wrong results

using cisco switches, I am trying to connect the output from ifHCInOctets to the names of the interfaces via ifName and comparing it to show interfaces counter. I use the last number behind the ...
0
votes
1answer
25 views

LACP - Load Balancing Network 2Gbit Ubuntu

I have configured my server as bonding interface to achieve 2Gbit network speed but it seems ubuntu can not go over than 1gbit and the outgoing traffic from server is not balanced over 2 interfaces. ...
1
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1answer
25 views

Debugging dropped UDP messages on Linux

Here's my setup: I have 1 host that has a 1 Gbit Ethernet connection and 2 hosts with 100 mbit connections (connected to the 1Gbit host through different switches). In a test, I send 1000 1kb ...
1
vote
1answer
38 views

Procurve Inter VLAN Routing

I have a VLAN routing issue on our network. We have two ProCurve 5406zl's being used as our core switches, each vlan on these switches has an IP address and VRRP is configured on each vlan for ...
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3answers
52 views

Connectivity between switches using SFP+

My office infrastructure is currently configured with HP Procurve switches. They are interconnected with 10Gbps fibre. All the SFP+ Ports are in use on all the switches. I am looking at buying a new ...
0
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3answers
51 views

Why another PC on lan can ping me even when I use /30 subnet?

Here is the set up: PC A : IP address : 192.168.1.2 Netmask : 255.255.255.252 Gateway: 192.168.1.1 PC B : IP address : 192.168.1.220 Netmask : 255.255.255.0 Gateway: 192.168.1.1 PC B is able to ...
1
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0answers
53 views

2 VLANs between four switches

I am having a problem that I do not quite understand with my network setup. I have four switches on the network: Switch A is a managed network switch which is connected to the PC router -- it is set ...
0
votes
1answer
16 views

Cannot access D-Link DES 3200-10 after resetting account

I've forgot my password and after googling I've found that in recovery mode I can reset my account. Connected to Switch using console port (VT100+ Keyboard compatible) and pressed Shift+6. I accessed ...
1
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0answers
23 views

More Management VLANS for a switch

I created a management interface in vlan 99 to telnet the switch (2900 series). I also wanted to configure another management interface for the same switch from the computer belongs to the different ...
4
votes
2answers
19k views

How compatible are sfp's really?

How compatible are sfp modules between devices. For example, am I likely to be able to plug something like this into a cisco, hp, or other switch with mini gbic ports? http://www.cdwg.com/shop/...
1
vote
0answers
34 views

VLANs with mixed MTUs trunked over a LAG

I'm contemplating enabling Jumbo frames for a specific network/VLAN (a dedicated storage network). Ports are spread across two switches, linked together using a LAG, which is configured to carry all ...
1
vote
5answers
12k views

Difference between trunk and tagged port

I am reading some wikipedia articles and RFC 5517, studying VLANs, and I don't recognize the difference between a trunk port and a tagged port. From what the material I am reading says, a tagged ...
2
votes
3answers
1k views

Layer 2 segmentation and network diameter

I am studying for my CCNA. The book makes a statement that I do not completely understand: "Layer 2 segmentation at the distribution layer practically eliminates network diameter as an issue." I'm ...
2
votes
2answers
6k views

Are you able to save the running-config on Nexus Switches

I have been trolling Cisco sites and have not been able to find an answer to this questions. Are you able to perform a write mem or likewise to save these configs on Nexus 5000 switches?
2
votes
1answer
396 views

Catalyst to Nexus Migration - Can 4948s be used for access switches

We currently have a switching topology in which two 7600 make up the core and there are N many access layer 4948s at the top of every few racks. They are trunked to both 7600s. I would like to ...
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0answers
7 views

Ceph Cluster Switch Specifications [duplicate]

What's more important when building a 10GbE Ceph cluster - switches that have larger buffers or switches that have less latency?
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votes
1answer
33 views

Set Internet Access for VLAN + Default Gateway + DHCP Client

I have a question that make my mind so bussy. I would appreciate if anyone guide me about this. So let me explain: Firstly consider We have bellow devices: Devices: 2 L2 Managable Swiches 1 ...
0
votes
1answer
25 views

frequent delay of 5-10 sec in sending commands from putty redhat. Why?

When we type a command from putty, it suddenly hangs for a period of 5-10 sec or more, but the commands are sent to terminal later. So seems to be a latency which occurs frequently. But, I might be ...
0
votes
0answers
21 views

Can't reach centos server after “Multicast listener report” IPV6

I ran into a problem that occurs only on a few servers. Every 5-6 minutes I lose connection to the server, and it get backs after a few minutes. In most cases it's a VM that is not reachable while ...
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0answers
17 views

Can I reset and access a Netgear GSM7532S without a serial cable?

I've recently been given a GSM7532S switch, however, I don't have any equipment with a serial port or have a serial cable. This device appears to have a web interface available but attempting to ...
0
votes
3answers
802 views

Is there a Cisco IOS command for finding out the serial number of a switch / router?

I am doing an inventory of all of our switches and I was wondering if there's a Cisco IOS command that will return the serial number for a switch and router? Thanks in advance!
0
votes
1answer
30 views

Networking related

I created two Vlans in a switch: Vlan 2 and 4. I want to access these two vlans in my computer without help of L3 switches. For this purpose I created port 24 as a trunk and directly connected to it ...
0
votes
1answer
46 views

Extreme Switch QinQ

Trying to configure QinQ solution between two extreme switches facing an issue: | Error: 8: Port cannot belong to VLAN and a VMAN at the same time.| This port is not configured in any VLAN or VMAN ...
0
votes
1answer
36 views

Intervlan routing--DHCP offer from server on default VLAN not making it back to newly created vlan via layer 3 switch

Default VLAN: 10.36.0.0/24 New VLAN : 10.36.8.0/24 DHCP server : 10.36.0.17 I can see the DHCP offer packets making it back to my VLAN ip address namely 10.36.8.31 (from dhcp server message log) ...
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votes
1answer
53 views

Point of Sale Terminal Crashing the Network

We look after a series of restaurants which is a collection of point of sale terminals and a typically a single workstation per site. We have one site that is causing a fair amount of head ache and ...
1
vote
1answer
608 views

DHCP Requests cannot get through Switch

First a little about the network setup: We are a smaller department of a larger school. We have 7 offices with TP-Link managed switches as well as 20 APs and 24 classrooms. The switches, APs and ...
3
votes
2answers
4k views

Cisco 2811 router ignored input errors

I've got a Cisco 2811 (AdvIPServices 12.4(25e)) that is showing input errors on both its interfaces, all the errors are of the ignored type. The counter for ignore errors is not increasing ...
0
votes
1answer
38 views

Set a upper bandwidth limit for Infiniband HCAs

I have to deal with PCIe congestion and I need to find a way to reduce PCIe traffic. I get several IB cards in one node (among other PCIe devices). HCAs are FDR Infiniband. Putting those HCAs in FDR-...
2
votes
1answer
665 views

Operational State Down on QLogic Switch

I have a QLogic SANbox 5800 Fibre Channel Switch with 20 SFP ports. Out of these 20, I can use only 16. The last 4 ports are showing Operational State Down. SANbox (admin) #> show port ...
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3answers
67 views

Configure small LAN to WAN network

I want to setup a small LAN that can connect to Internet via my ISP's router (I have only one open port on my ISP's router and 6 public IPs). On my side, I have an Ubiquity Router that I connect to ...
1
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0answers
23 views

How should I use Cisco ASA 5510 and Catalyst 3550 together

So I took on a project at my job moving four separate networks into one Colo center. Currently I broken everything down from the four networks into 4 VLANS on the ASA 5510. Each are assigned IPs ...
-1
votes
1answer
75 views

Connecting Win7 to Win7 through switches, EnGenius, and Routers

Weird networks, causing weird problems. I am a new employee at this company, the network is a bit weird, but I have figured it out to a degree. I have some networking knowledge, but not greatly versed....
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votes
0answers
15 views

How to make D-LINK switch IP permanent

I have procured a new D-Link Switch. I have changed its default ip address from 10.90.90.90 to a new ip address. eg - 192.168.100.101. But I am unable set the ip permanently. Whenever I power off the ...
2
votes
2answers
22k views

Configuring VLANs on HP 1910 switch

I understand how VLANs work, but am not quite sure what the various settings in my HP switch actually do. I have an HP 1910 switch, and I'm using the web interface to configure it (personally I'd ...
-1
votes
1answer
36 views

How are IP packets routed from LAN to WAN? [closed]

I have OpenWRT set up on a router, with a wireless client connected on the LAN, and connected to another network on the WAN. wlan1 is bridged on the br-lan interface, and typically forwards to the LAN ...
-2
votes
2answers
67 views

connecting two switches with different ip ranges

I have two switches that assign different DHCP IP addresses. one assigns 192.168.0.x to devices that are connected to it and the other one assigns 10.0.0.x ip addresses. Is this the reason I cannot ...
3
votes
3answers
11k views

How many switches can be stacked/interconnected?

I would like to know how many switch can be stacked with fiber channel to get a best transfer rate between computers. I have 200 computers connected to 12 3Com switches. All switches have two fiber ...
1
vote
2answers
62 views

VLAN sending data to ports it shouldnt have to

I noticed (based on activity lights) that VLAN traffic between two switch ports are being sent to many switch ports. Here's my scenario: Port 1 is a "mode access" switchport for VLAN 100 (untagged ...
-1
votes
1answer
53 views

Netgear Switches GS748Tv4 and v5 ports go down and up and Spanning Tree Topology Change

I'm getting notifications on my Syslog server from the Netgear switches GS748Tv4 and v5. These are the notifications: traputil.c(696) 122305 %% Link Down: g30 traputil....
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0answers
30 views

Configure Cisco QoS for VLAN

I have two VLANs (20 and 21) that are accessing the same resource on a switch. Clients on VLAN 20 access this resource only at schedule times, but when they do, they generate lots of traffic as they'...
4
votes
2answers
4k views

Switch Floods Packets that should be Unicast

I work as a Network Admin in a big company. Lately we noticed an issue with our network infrastructure. Basically our network backend lies on a Catalyst as main L3 backend switch, and few Cisco Nexus ...
1
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0answers
154 views

Zabbix drops in SNMP from Cisco SG200 switch

I'm using Zabbix 3.0 to monitor our main switch in which the port from the firewall as well as other ports show what appear to be drops of either sending or receiving. One would conclude that if this ...
1
vote
3answers
49 views

Network adapter only works with ethernet switch

I have a Dell XPS13(Win 10 Pro) and since we dont have wireless lan in the office i had to buy an external ethernet adapter (DA200). The adapter works perfectly fine at home but it doesnt work at all ...
1
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0answers
42 views

When a computer wants to send a IP packet to another computer in the same network, how does it know the destinamion MAC address of that host? [closed]

So I know that switches are better than hubs because they can forward an Ethernet frame exactly to the host that has that specific destination MAC address. However, when two computers communicate, ...
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votes
1answer
135 views

ZyXEL switch management port configuration [closed]

I'm a total newbie in configuring a network switch and I would like to know how can I configure the management port of a ZyXEL switch. I have a ZyXEL XGS3700-24 model and I set an IP address like 192....
0
votes
0answers
20 views

PCIexpress switch mixed gen2/gen3 behavior

For a PCIexpress switch with a physical gen3 x4 upstream, and two downstream devices each with x4, what is the expected speed/performance behavior when Downstream device 1 is gen2 x4 and downstream ...