For questions related to traffic switching and troubleshooting the traffic switching process.
8
votes
3answers
770 views
Is there a performance difference between a managed an unmanaged network switch?
Is there a tangible difference in speed/latency between a managed and unmanaged network switch?
2
votes
2answers
31 views
Can Multicasting be duplicated by broadcasting on a subnet?
Is there any functional difference between:
A) Broadcasting to a range of addresses
B) Putting the range of addresses into a subnet and broadcasting to that subnet
Would it matter if there was a ...
0
votes
1answer
39 views
from where/how is the figure of 50 m sec protection switching time calculated in case of ERP/ MPLS?
From where or how does the figure of 50 m sec protection switching calculated for MPLS/ ERPS?
1
vote
1answer
44 views
Network ( routing and switching) , security
In my company network i am installing new cisco2811 router but i have problem, my LAN network can not ping and access network. i get point to point internet from ISP.
PTP IP is 192.186.86.200/24 and ...
1
vote
1answer
43 views
Understanding IP multicast in linux [closed]
My ultimate goal is to setup IGMP snooping on a linux machine using netfilter hooks. This is for exploratory purposes to understand IGMP protocol.
The topology we are using is as follows:
| ...
1
vote
2answers
33 views
Cisco router with switch interfaces help
I was wondering if a connection comes in on a Cisco router interface. Can that connection be pointed towards a switch interface if said router has a switching module?
I haven't tried it, but I'm ...
0
votes
2answers
34 views
Layer 2 Routing between subnets and VLANS [closed]
I am studying for my Networking exam and from what I have pieced together from other posts on here is this. Please correct me if I'm wrong:
Layer 2 switches can only route packets between different ...
2
votes
1answer
72 views
Using IGMP but Multicast still Flooding
Im new here.
I want to ask about the multicast,
The first case is, I have switch HP 2530 24 port with 24 10/100 and 2 100/1000 NIC, And i have servers with bandwidth video multicast around 120-...
1
vote
1answer
42 views
Help this problem with Dhcp Server with two switches
I will try to explain my problem. I am trying that Switch 1 can give dhcp for pcs but i cannot, in Switch 0 I can give dhcp server in the pcs. sorry for my bad english
ROUTER
!
version 15.1
no ...
0
votes
2answers
36 views
Advice on potentially needed subnet expansions
I work for a non-profit with some slightly more antiquated hardware. We have 3 locations, about 700 devices across them. Right now our locations are set up as:
Location 1 (Main) - /23 with a DHCP ...
0
votes
1answer
52 views
Is forwarding rate important for selecting a collapse core switch in IP camera implementation?
I need to select a core switch that will connect my access switch to an IP surveillance's server. The point is that in my network I'll have 109 IP camera sending real time traffic to the server and I'...
4
votes
2answers
70 views
Network Ten LTE Hubs Into One Network
I'm working through a tricky situation getting a field office set up out in a very rural area. There are ten 12' x 60' trailers being set up (2-3 metres apart from one another), each with varying ...
2
votes
2answers
41 views
Cisco Router 1800 series doesn't route internet
Working on an issue with a 1800 series Cisco Router. Router get's Internet just fine, can ping Google, Microsoft, etc.. Router is connected to a switch, switch connects 2 workstations running Windows ...
1
vote
2answers
38 views
Cellular signal handoff
In a cellular network like T-Mobile, Sprint, etc. if one sector of a tri-sector tower is maxed out and can't accept new calls, will a new call request normally served in that sector be handed off to ...
2
votes
1answer
68 views
Packet vs Circuit switching
I have a 1Mb/s link each user uses 100Kb/s when active.
With 10 user active 10% of the time, I can have 10 users in a circuit switched environment. Packet switching with 35 users, probability > 10 ...
1
vote
1answer
28 views
Circuit switching. How is the data rate divided for each circuit in a link for FDM and TDM?
FDM allocates portions of bandwidth to each circuit in the link. According to the Nquist equation, this would propotionally divide the data rate among the circuits.
Now with TDM time slots are ...
2
votes
1answer
98 views
End-to-End delay
I’m working through questions from computer networking top down approach and was hoping to get some clarity on the end-to-end delay calculation. At this stage we are not considering processing, ...
0
votes
1answer
39 views
Frame transfer from one switch to another configured with VLANS
Hi,
My question is related to the Vlan. And this question would consist of 2 parts.
1)Would Switch 1 know all the devices present in Vlan 2 or Vlan 3, including the ones present in the Switch 2.
...
1
vote
2answers
73 views
Multi Chassis Ether Channel Best Practice
in our topology we have our Data Server(Multi Virtual Servers) and Backup Server exist in two different buildings and the current connection between them as below:
Connection explanation:
*1st ...
2
votes
1answer
72 views
Why switch has records in mac-table when i just set ip address to the hosts which connected to the switch?
I created a new switch and connected to two hosts in GNS3.Like this:
Host1--->LS<---Host2, i think the mac-table in the switch should be empty before i sent data between two hosts. But when i just ...
1
vote
1answer
26 views
SNMP returns strange “bits sent/received” values on a particular port, why?
I have a HP V1910 Switch in my office. I have set up monitoring via SNMP on my local Zabbix server, and everything looks really good on almost all ports (for example, when I use iperf to test ...
-3
votes
4answers
159 views
Can we run the Internet on circuit switching?
Generally we use IP and ATM for data communication and can we use circuit switching for data communication ?
Can we use circuit switching for Internet ?
4
votes
1answer
128 views
QoS Policing vs Shaping, why policing
Regarding QoS, we have two modes: shaping or policing.
The policing drops packets while shaping put the packets in buffer.
Shaping seems to be the better solution in a general ways, so, why use ...
0
votes
1answer
106 views
Cannot ping or SSH into new Catalyst 2960-CX switch from the server VLAN (1)
I recently setup a Cisco Catalyst 2960-CX switch at work (I'm a SysAdmin at a SMB). Our workstations use VLAN 3, but our servers use VLAN 1. The management IP of the new switch (in VLAN 3) is 192.168....
1
vote
0answers
46 views
Cisco stacking - priority and number information
In case of switches stacking, where are stored the information about the switch number and the switch priority ?
After a reset, these information were conserved.
1
vote
1answer
42 views
Calculating buffer capacity
The serialization delay is the amount of time it takes to forward bits out of an interface. A 1 gigabit per second interface can send 1 billion bits per second. One billion bits per second equates to ...
3
votes
2answers
811 views
Does it make sense to map a VLAN to each LAN?
I saw a picture of a network-structure with VLANs in it:
Why would somebody structure their network like this? Does this even make sense? I mean, they are in a different LAN, why then mapping a VLAN ...
2
votes
1answer
136 views
Really basic SG300 VLAN setup not working
My understanding of VLANs may need improved, but isn't the idea that you can run multiple LANs at layer 2 level over the same router if VLANs are setup correctly on the SG300? If so, I fail to see how ...
2
votes
1answer
48 views
Spanning tree behaviour - topology change
Regarding a next change we have to do, we are studying spanning tree behaviour.
Does the following statement is true ?
In the case of topology change, if a new BPDU is received:
Currently: Root ...
0
votes
1answer
29 views
What switching methods do SOHO switches use, like in cisco switches used?
Switching methods like,
Store and Forward
Cut-Through
Fragment-free
2
votes
0answers
97 views
Cisco: Routing issue between LANs [closed]
We have a project to create 3 offices, which are 3 different LANs where the configuration should be as follows:
Each Office should have 1 printer, where the office is able to print
They should be ...
1
vote
1answer
63 views
How to create vlan for admin?
I wanted create a separate vlan for admin and give access to other vlan , so what is the procedure or method to do it?
1
vote
2answers
257 views
Gratuitous arp and unicast flooding
we have few 100s of access switches connecting to a core 10k in IRF. Here all our access is pretty much dumb does only L2 job. So what happens now is unicast flooding, technically MAC ages out, ...
2
votes
1answer
50 views
Frame relay, PVC and DLCI
Regarding the frame relay technology, could you confirm to me that traffic using permanent virtual circuit use the same ISP routers in the path for all packets sent ?
I'm a little bit confused.
Frame ...
5
votes
1answer
183 views
Cisco Catalyst Line Cards - memory considerations
Do the Catalyst Line Cards (4500 and 6500 series) hold memory (kept after reload), or some other information independently of the Supervisor Card?
I ask regarding a chassis reset process, in order to ...
-1
votes
2answers
38 views
Can a switch segregate traffic that is before the switch from after the switch?
Per the question, Lets try to clarify a bit. Can a switch that has a router connected to it, segregate traffic (using a VLAN) from traffic that is part of the modem/router the switch is connected to?
...
0
votes
2answers
36 views
Setting up a hypervisor network
I have a pfsense appliance that serves as my router. I have four hypervisors that I want to hook up to one of the router interfaces through a switch. The hypervisors will house multiple VMs that are "...
0
votes
2answers
644 views
Solving Native Vlan Mismatch error
I am new in VLANs , im currently trying to complete this topology however i can see the following errors on all the three switches:
EX:
%CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered ...
3
votes
2answers
194 views
Control plane terminology - Cisco Nexus
Is it true to speak about layer 2 control plane (LACP, STP, etc), and layer 3 control plane (OSPF, EIGRP, etc) ? or do we have only a general control plane ?
We know Cisco Nexus vPC cluster has a ...
0
votes
2answers
65 views
What does ethernet switch do with IP address [closed]
Sorry about asking stupid question here but I'm very new to this field...
Here is my current set up:
_____ NAS
|
Modem --- Router --- Server
|____ ...
4
votes
3answers
288 views
Theoretical: Bottleneck in a switch stacking environment
Quick question regarding stacking environments and their limitations regarding traffic bottlenecks.
Assuming the following use case:
We have a stack of 8 switchs, forming a Half 10Gbps stack ring.
...
1
vote
2answers
119 views
Endpoint MAC address change detection [closed]
A question regarding a host behavior when gateway mac address has changed (although it deals with Windows, I think it's the best forum).
Assuming a windows host sending trafic to a destination IP, ...
3
votes
2answers
74 views
Any reason to use hubs?
Given that hubs are essentially the same as switches, as far as I know, except they share bandwidth between all connected devices, while switches do not, resulting in faster connections. I am simply ...
0
votes
1answer
63 views
Isolating a NAS using VLANS and netwgear layer 2 switches
I have a NAS which is used locally by a computational cluster that I would like to isolate from the corporate network. I have a netgear GS752TXS that connects the various nodes of the cluster as well ...
1
vote
2answers
99 views
CSMA/CD - CSMA/CA switch mix
Suppose I have 2 switches; one CSMA/CA (gigabit) and the other CSMA/CD (gigabit), would they work together when connected and if so would there be any dip in network performance?
Thanks in advance!
3
votes
1answer
123 views
How would I configure etherchannel for this particular topology?
How would I setup and configure etherchannel from switch0 to all the other switches?
Switch0 has been configured as the root bridge, Router0 has been configured to be the gateway for each Vlan and as ...
3
votes
1answer
249 views
Cisco MLS and MQC QoS - trust cos/dscp
A question about Cisco MLS and MQC QoS.
I read two things on a Cisco guide: https://www.cisco.com/c/en/us/support/docs/switches/catalyst-3850-series-switches/118629-technote-qos-00.html
On the ...
2
votes
1answer
325 views
MLS QoS to MQC conversion
Currently trying to convert MLS QoS to MQC QoS, I'm facing a problem.
In MLS (3750), and auto QoS we have this configuration for INPUT QUEUES:
mls qos srr-queue input bandwidth 90 10
So in input 90% ...
1
vote
1answer
43 views
Can you vlan tag and assign a priorty (0-7) to SCP traffic
My question is in relation to the file transfer protocol SCP. I have a local time sensitive network built. In time sensitive network you can give priority to traffic by vlan tagging and assigning ...
2
votes
2answers
54 views
Intermittently loose communication with upstream managed switch
I have a network for a small company that has been running without an issue for a few years. We have Cisco IP phones on VLAN 100 and computers on VLAN 1. The VLANS are auto assigned by the Cisco ...
