All Questions
16,664
questions
2
votes
1
answer
68
views
cisco catalyst 6500 not honoring static ip assignments
I have a catalyst 6500 sup720 running 15.1(2)sy6 and i have attempted to have a set of mac addresses to get a specific ip from dhcp. below is what shows on the bindings.
10.1.4.200 01e0.508b....
- 373
0
votes
3
answers
56
views
Is there a difference between NetID and Network Address?
So i know the gist of it. Thanks to the help here
Network Address i see as anything ending with 0
Example: 192.168.0.0
Broadcast Address i see as anything ending with 255
Example: 192.168.0.255
...
- 32.2k
1
vote
2
answers
124
views
Why are DNS packets processed by process-switched?
I have a question.
Equipment: Cisco 2821
CEF is enabled on all router ports:
sh ip interface | i CEF
Post encapsulation features: CEF Packet Capture
IP CEF switching is enabled
IP CEF ...
- 29
0
votes
2
answers
30
views
Does Ethernet work at the FLIT level?
Does Ethernet work at the FLIT level? If yes, then how are the frames converted into flit and vice versa?
If not, then what's the reason?
- 84.4k
1
vote
2
answers
305
views
bgp and routing
I need a bit of help understanding what is going on in my topology.
I really want to understand why i can ping 1.1.1.1 from r4 but not from r5 or r6.
Please help and advise me.
Many thanks guys
r1
...
CommunityBot
- 1
0
votes
1
answer
519
views
Ping to default gateway failing
I am trying to ping to a default gateway which i have configured as 171.2.0.1 but somehow the ping is failing . I am new to network domain so i have less idea about it . Any help is appreciated .This ...
CommunityBot
- 1
1
vote
0
answers
36
views
L2 Circuit ober BGP Signaled MPLS
We are providing MPLS Network services to Customers via Ethernet Links. Our CPEs (mainly Cisco) are linked via VLAN Subinterfaces to the PEs (Juniper MX). Due to the increasing demand of Multiple ...
- 536
1
vote
1
answer
38
views
IPSec Site to Site VPN Connected but Subnets not Routing [closed]
Re: Creating a site to site vpn from ubuntu 22 + strongswan to cisco meraki
Issue: I've established a vpn tunnel but routing between clients on the network is not working.
meraki config:
Non-Meraki ...
- 111
0
votes
1
answer
37
views
Interesting Traffic and Management Traffic
I am trying to understand the types of traffic the NSOC deals with when updating devices across the gateways or even local to the NSOC.
Can anyone help me understand the types of traffic that there ...
- 19.6k
0
votes
2
answers
459
views
snmpwalk returns hex-string for interfaces without a description
nterfaces with an actual description are returned as a string, for example the interface with Device1ILO
However the interfaces without a description configured, are returned as Hex-STRING 00.
How can ...
0
votes
1
answer
59
views
Logic of subnetmask 255.255.255.252 networking in Packet Tracer
We have an assignment to connect computers to each other using this system.
I tried changing from FastEthernet to GigaEthernet and then adding this cross connection. Which our teacher says is the ...
- 19.6k
1
vote
1
answer
3k
views
Traceroute through IPSec tunnel
askk
Hi. When I do traceroute from host 192.168.11.0/24 to the server 10.0.0.0/24, which is site B. When the packets get into the public area it show Request timed out (as shown in this figure). I'm ...
CommunityBot
- 1
0
votes
0
answers
24
views
LTE network open for all users (no AKA procedure)
I was wondering if there is some way a LTE network can operate in a way that it allows any user to connect to it without having to be registered on its HSS database.
I know the normal mode of ...
- 1
1
vote
1
answer
33
views
What is the usage of PVCs in an ADSL modem settings?
This is a question from a layman searching for practical information. I can see eight PVCs in the settings of this ADSL modem. Just one of them is connected. As far as I know, they define some sort of ...
- 84.4k
0
votes
2
answers
607
views
Copper or Glass for Low Latency?
I'd like to preface the main content of this post with the following: I understand this question may be equally suited to the Physics Stack Exchange, and so I have posted on there as well, but maybe a ...
- 84.4k
0
votes
1
answer
30
views
Public wifi router conflicts with company VPN IP address [closed]
I'm a digital nomad and I like to work in cafes and co-working spaces. The problem is that sometimes the network router IP address conflicts with my company's VPN-client IP address.
Any and all ...
- 32.2k
0
votes
1
answer
51
views
Limit on how many times on converting fiber to copper vice versa
I need to run data through single mode fiber (1.5km) to connect to a remote site. I have to cross a road that has a copper data cable run underneath it. (cat5e) The local authority doesn't allow me to ...
- 13.3k
0
votes
1
answer
78
views
Change source and destination adresses from a valid captured ping to create a valid ping with different source and destination
I want to create traffic in my network, especially
I want to send a repetitive ping to the device with the IP 192.168.3.146 from my traffic generator (IP 192.168.3.100) (see scematic)
For the creation ...
CommunityBot
- 1
0
votes
2
answers
55
views
Different speed between daisy chained switches
What happens with the network link between the PC and Server if the architecture is as follow:
If the Client request UDP-traffic and the Server response will be 1Gbps UDP traffic. Would this result ...
- 84.4k
0
votes
3
answers
192
views
Direct connection slower than via switch
My office ISP provides a 1 GBPS connection. When I connect my laptop directly to the router provided by the ISP, and connect to fast.com, I get a speed of approximately 100 mbps.
Our office network is ...
CommunityBot
- 1
2
votes
1
answer
1k
views
Is NAT hole punching feasible, when the external source port of NAT changed for different destination?
I have a question about hole punching.
A-Client
B-Client
S-Rendezvous server
Both A and B connects to S. S learns the random NAT ports of clients. Then sends the IP/Port info to clients. Clients ...
8
votes
2
answers
2k
views
UDP hole punching when NAT port distinguished for every outgoing UDP connection?
I just read an article about the process of "punching holes" with the UDP protocol. I understand how it's done, but I have one last question to clear up things. We have the rendezvous server and ...
1
vote
1
answer
74
views
Why does 1000BASE-T require a crossover function?
IEEE 802.3-2018 §40.8.2 Crossover function reads:
Although the automatic MDI/MDI-X configuration (see 40.4.4) is not required for successful operation of 1000BASE-T, a crossover function must be ...
CommunityBot
- 1
0
votes
1
answer
42
views
How to access SVI from the other side of a tunnel? [closed]
With two vlans separated by an IPSec tunnel, I'm having issues reaching an SVI on the far end. Hosts on either end can ping each other without issue, but the SVI's do not respond from the far end, ...
- 84.4k
0
votes
0
answers
38
views
what do the two parameters SINR and RSRQ mean in 4G routers and what is the difference between them?
I want to know what do the two parameters SINR and RSRQ mean in 4G routers and what is the difference between them?
- 84.4k
0
votes
3
answers
4k
views
Cannot create subinterface
I'm trying to connect 4 networks with 1 router, i created 2 sub-interfaces in the router, when i tried to create the 3rd sub-interface i got this output "%Cannot create sub-interface", this ...
CommunityBot
- 1
0
votes
0
answers
14
views
Gigabit Ethernet downgrading to Fast Ethernet - can it tolerate loss of any individual wire? [duplicate]
I have read that a damaged cable that used to work at 1000 Mbps can still be used at 100 Mbps. Does the specific wire inside matter? Say, wire 1 being damaged versus wire 5 or 8? Will two auto-...
1
vote
1
answer
72
views
Iperf testing- Slow transfer speeds [closed]
I'm doing Iperf testing at my company's branch office circuit and I'm getting results that are causing me concern.
I'm testing from a laptop through an access switch>distro switch> Fortigate> ...
- 19.6k
0
votes
1
answer
123
views
Is this the right way to expose VLANs through VPN (VPN server location)?
Starting from the following network topology:
Internet --- ISP Cable Router --- Firewall --- Router --- rest of the network / multiple VLANs
(port forwarding) |
...
CommunityBot
- 1
0
votes
1
answer
34
views
Communicating Between Two Devices When One Lacks Internet Access
I am currently developing a software that needs to establish communication between two devices. Device 1 has internet capabilities, while device 2 may not always have internet access. I am ...
- 32.2k
1
vote
2
answers
600
views
High-Resolution Measurement of link utilization of Cisco (Nexus) Switch Interfaces
For a research project I need low timescale interface utilization measurement on a Cisco Nexus 5000 devices and some fabric extenders.
Background: The switch is used to "simulate" an optical network, ...
- 1
0
votes
1
answer
48
views
How is routing precedence determined in DHCP Offer and Acknowledgement packet from server?
I'm learning about the DORA process in TCP IP. And the way server communicates with client is very "confusing" to me.
Let's take an example of DHCP Offer:
At this point, the client is still ...
- 84.4k
1
vote
0
answers
29
views
DORA process TCPIP [duplicate]
http://www.tcpipguide.com/free/t_DHCPGeneralOperationandClientFiniteStateMachine.htm
I'm reading through the entire Discover, Offer, Request, Acknowledgement phases in DHCP. And I am really confused. ...
- 84.4k
1
vote
2
answers
75
views
VoIP SIP PCAP issue
I have a question for anyone who might know the answer. My boss has asked me to PCAP a SIP stream from a VOIP phone by plugging my laptop into the same unmanaged switch, without enabling port ...
- 84.4k
1
vote
1
answer
192
views
Communication between hosts on different local networks
I understand how NAT works in case of communication between one, local host and a server with specific public IP address. The host is sending a request, it pushes the packet with destination IP ...
CommunityBot
- 1
1
vote
0
answers
44
views
Need for additional Master Port Role in MSTP
MSTP IEEE specification, it says the Root Port for CIST will be the Master Port for all MSTIs. I'm wondering what is the need for this additional port role, is it just to isolate the region boundaries ...
- 11
0
votes
2
answers
173
views
Cisco ASA access-lists and net config
Here are my config to this network. I found the ASA doesn’t ping through each other. Also, when I type show crypto isakmp SA and IPSec Sa, it doesn’t show anything at all. Could you guys find what’s ...
CommunityBot
- 1
0
votes
1
answer
37
views
Scenarios in which a host (e.g. Debian) would update its ARP table [closed]
For security reasons, I'd like to know for which of the following scenarios would a host (Debian for example) update its ARP table:
It receives a gratuitous ARP for IPs that are not in its ARP table
...
- 273
1
vote
2
answers
88
views
What is the time of sending/receiving a network packet comprised of?
When I do a traceroute, I can see the round trip time in milliseconds or "ms", for my packet(s) to reach that point and return to my computer.
Let the round trip time be the variable x. For ...
- 84.4k
1
vote
1
answer
85
views
How to configure OSPF to create desired routing paths?
Is there any way to assign OSPF cost so that when is traceroute 147.147.11.98 from R1
it goes like R1->R4->R5->R2
and when I traceroute 147.147.11.98 from R5
it goes like R5->R4->R1->...
CommunityBot
- 1
1
vote
1
answer
25
views
Cisco QSFP loopback device recognized but 'not connected' with status light off
I have tried plugging a QSFP28 loopback device into port on a cisco switch. I can see that the chip is recognized when I do 'show interface status' as I can see the model listed but it is 'not ...
- 17.4k
2
votes
0
answers
2k
views
RSA key not working with trustpoint used for IPSec
I'am trying to setup an IPsec IKEv2 tunnel where the local authentication mechanism is based on RSA. Therefore I have setup a trustpoint and I got a signed certificate for this setup.
Importing is ...
3
votes
0
answers
248
views
Router as PPPOE concentrator, PPPOE clients unable to get to DMZed static NAT server
I've been trying to figure out this problem, and I'm just not up to the task.
I have a Cisco 2911 router as follows:
Internet connection on GigabitEthernet0/1.
Which has it's own static IP: A.B.C.38/...
1
vote
1
answer
54
views
ARista 7280SR-48C6 routing table size
i want to use a 7280SR-48C6 as edge switch and i read arista datasheet but i could not find how many ipv4 and ipv6 it can hold. can i have 4-5x IP transits with full tables and 30-40x private peering ?...
CommunityBot
- 1
2
votes
1
answer
135
views
which protocol is invoked first by routers ? routing (routing table) or ARP?
I have a question regarding the internet layer of the TCP/IP model: When a data frame is sent by a client to a server located on another network, we know that the routing tables and the ARP protocol ...
- 84.4k
1
vote
1
answer
56
views
Firmware version K.15.15.XXXX for HP J9477A Switch E8206zl not found
Does anyone know where I can find any K.15.15.XXXX firmware version for HP J9477A Switch E8206zl switch?
I could get my hands on K.15.18.0021 but the release notes is not helping me regarding the ...
- 84.4k
0
votes
0
answers
27
views
beacon interval & number of APs benefits/downsides/
As far as I understand, A beacon announces an AP's availability & capability, to allow clients to make decisions about which AP to connect to, does this mean it matters less the less APs are ...
- 1
1
vote
6
answers
1k
views
What happens to the unused IP addresses in the subnet that falls in between two routers?
This is probably a un-realistic question, but a question nonetheless, that has been bugging me since quite a while now.
Consider the below network diagram, where R1 is a part of a 10.0.0.0/8 network (...
- 11
1
vote
1
answer
324
views
DDNS for Palo Alto Behind NAT Internet
We would like to configure SDWAN for our branch site that only has broadband internet. In order to do that we need to know from which public IP does the PAN use to initiate the SDWAN. Because the ...
CommunityBot
- 1
2
votes
2
answers
66
views
what information needs a router to make a decision?
How does a router that receives a packet know what to do if it doesn’t know the subnet mask of the IP that sent the packet? The reason for asking this is that I didn't see any field in the IP header ...
- 1,614