Most Popular
1500 questions
7
votes
3 answers
Does it make sense to generally "Disable TCP Checksum Offload"?
In a work sheet for PCs that we deliver to customers, I found instructions to always "Disable TCP Checksum Offload" on the NICs. Via those NICs, the PCs are connected to the customer's LAN, and it is imperative that they work without problems.
The…
doppelfish
- 173
- 1
- 1
- 5
7
votes
4 answers
Are multiple links with different VLANs between two switches possible?
I'm not considering Etherchannel or LACP.
Given 2 Ethernet switches A and B, where both switches have port 0 configured as a tagged trunk for VLAN 100 and 101 and port 1 configured as a tagged trunk for VLAN 200 and 201. Can I connect port 0 on…
nos
- 763
- 2
- 8
- 14
7
votes
2 answers
Is it possible to emulate device other than Cisco and Juniper in GNS3 or any other environment?
For testing and research purposes, I know it is possible to emulate Cisco devices (with dynamips) and Juniper ones (via an "Olive", a FreeBSD based system running on qemu) in a GNS3 environment.
Is it possible to emulate other vendor devices (like…
Benjamin A.
- 1,697
- 2
- 15
- 27
7
votes
1 answer
Why do we have authentication before association in 802.11
Why does client authenticate before associating with the AP. What does open system authentication even achieve. I fail get an accurate reason from my web searches. Best reason I do get is unlike wired medium there is no concept of physical port in…
Ganapathi Bhat
- 85
- 5
7
votes
5 answers
OSI layer of Neighbor Discovery Protocol
NDP operates using ICMPv6 and, even though ICMPv6 messages are encapsulated in payload field of IPv6 datagram, ICMPv6 and ICMP are usually considered as network layer protocols. At least, on Wikipedia they are network layer protocols.
So I thought…
JenyaKh
- 245
- 1
- 7
7
votes
1 answer
Is the first address of the subnet a valid configurable address in case of IPv4 and IPv6 point to point networks?
Am I correct, that first address of the subnet is a valid addresses to configure in hosts/routers in case of IPv4 and IPv6 point to point networks? For example, in case of 192.0.2.0/31 one of the hosts would get 192.0.2.0/31 and the other would get…
Martin
- 1,233
- 6
- 26
- 51
7
votes
2 answers
Cisco Catalyst cluster heartbeat switch issue - increasing input errors
PROBLEM:
The servers in two clusters keep losing heartbeat connectivity with each other thus causing database outages. Outages are brief but disruptive.
SETUP:
There are two clusters of three servers each.
Each server has one NIC connected to a…
VMEricAnderson
- 538
- 4
- 18
7
votes
0 answers
HSRP IPv6 configuration
Looking at the Cisco documentation for HSRP IPv6 configuration I noticed the use of 'standby 1 ipv6 autoconfig'.
interface FastEthernet0/0
no ip address
duplex auto
speed auto
ipv6 address 2020:AB8:2001::1011/64
ipv6 enable
standby version 2
…
dcrearer
- 499
- 2
- 4
- 16
7
votes
1 answer
Cisco BGP Graceful Restart behavior
In our environment we generally have ASR-1000X-2s everywhere peering via iBGP/eBGP. These routers have no redundant RPs, hence cannot keep forwarding traffic while the router reboots or crashes. As such, this is a clear example of a router that's…
Con7e
- 71
- 1
- 5
7
votes
1 answer
How to set IPv6 RA values for RDNSS and DNSSL on HPE/Aruba 5400R
I am detail-planning the roll out of IPv6 in our company.
Right now I am stuck with IPv6 RA on our HPE/Aruba Access Switches. I cannot find any documentation how to set the Recursive DNS Server (RDNSS) and DNS Search List (DNSSL) values in the RA.
I…
Andreas Rogge
- 211
- 1
- 6
7
votes
1 answer
DCF and PCF in Wifi-networks
I am studying, trying to learn how DCF (Distributed Coordination Function) and PCF (Point Coordination Function) works as access methods in WiFi, and how they relate to infrastructure vs ad hoc networks.
My teacher in this course has claimed that…
martinr
- 73
- 4
7
votes
3 answers
Posible to connect VLAN switch through dumb switch?
Is it possible to connect a VLAN switch into a dumb switch ?
The router will know how to reach network connected by a VLAN through the dumb switch please ?
No edge effect ?
By example, a schema of the project :
Thanks !
Puma
- 71
- 1
- 3
7
votes
3 answers
OSPF and its use of Multicast
When it comes to OSPF and its use of multicast, am I correct in believing that IGMP forwarding and an IGMP querier is still required within the local segment?
My understanding would be without this, the frames would be treated as a broadcast and…
RickD
- 269
- 3
- 13
7
votes
2 answers
How the packet is routed between two host from same sub-net and associated with same AP?
Given host 'A' and 'B' have IP 10.10.0.5 and 10.10.0.8 respectively, the sub-net mask for both are 255.255.255.0, both 'A' and 'B' are associated and connected to the same AP, and the AP is connected to a switch at the interface 'X'.
'A' sends some…
H.Jamil
- 95
- 6
7
votes
2 answers
How is the Groupwise Transient Key used in WiFi networks?
In Wifi WPA, I understand that during association, a 802.11 client and AP negotiate a Pairwise Transient Key (PTK), using which the Groupwise Transient Key(GTK) is provided to the station.
I understood recently that all communication from/to this…
Sush
- 217
- 1
- 5