7
votes
Will STP lose data whilst switching from a failed link?
If i remember, default spanning tree (802.1d) takes about 50 secs to reconverge. That is the duration for which you will be losing frames.
A link is detected down by the loss of 10 hello pkts. These ...
- 585
6
votes
Accepted
HSRP change priority didn't failover
You forgot to use the standby 5 preempt command. It is also a good idea to set a preempt delay.
Hot Standby Router Protocol (HSRP): Frequently Asked Questions:
Q. Which HSRP router requires that I ...
- 98.8k
5
votes
Accepted
Choosing between BGP (AS Number) and Dynamic DNS
DynDNS
Using DynDNS is not a viable solution for your usecase since its primary use case is mapping a dynamic ip address to a dns record. If you have two Upstreams with different ip subnets you would ...
- 767
5
votes
Accepted
Multhoming including incoming connections?
You're mixing up terminology a bit here. There's no such thing as an IPv4 ASN or IPv6 ASN. There's IP space, which is either IPv4 or IPv6, and there are ASN's. An ASN can announce IPv4 prefixes, IPv6 ...
- 17.1k
5
votes
Accepted
EIGRP failover - how do i verify it happened?
There is a command made for such checking. Use:
show ip eigrp events
- 651
4
votes
Accepted
ASA5550 manual failover question
How do i check the status of failover to make failover is correctly
configure.
These commands will give a good indicator of the status and configuration
show failover
show failover state
show ...
- 1,241
4
votes
EIGRP failover - how do i verify it happened?
Yes, you can confirm that. Once hold-time expires, the former
feasible successor route immediately becomes the successor route and
is installed in routing table.
I do not think we have a log message ...
- 3,754
3
votes
Failover with two ISPs, one with public and one with private addresses
Putting aside the question of why you are using public addresses in your network for a moment, you would configure this the same way if you were using private addresses: you configure NAT (actually ...
- 67.1k
3
votes
Accepted
Failover with two ISPs, one with public and one with private addresses
That depends on whether or not you need to public addresses to be available outside you company. If so, you are going to need to work with the ISPs to set up BGP routing with them.
If you don't need ...
- 98.8k
3
votes
Accepted
Lowest Possible Failover Latency
Failover time is going to be dictated by two chief factors:
1.) Time to detection - How quickly the connected systems can determine a link has failed.
2.) Time to convergence - Once the failure is ...
- 6,104
3
votes
Accepted
WAN failover when links stay up/up
Based on your question about the routing protocol, I will assume you are not running one, but you are using static routes, probably static default routes.
You could use a routing protocol, but you ...
- 98.8k
3
votes
Accepted
How switch divert traffic to standby ASA when link to active ASA is down?
Switches only forward frames based MAC address. The secondary ASA takes over the MAC address of the failed ASA.
Cisco has an explanation of the process.
- 98.8k
3
votes
2-stacked switches with 2 uplinks to each ASA
Using a 2nd Uplink and using link aggregation (etherchannel) is the right way to go. Keep in mind that your throughput problems might be due to the ASAs limitations (which model do you use?)
Another ...
- 767
3
votes
Accepted
ASA Redendent Failover and stateful link issue
"Everything working good but when i remove g0/6 cable..." --> Does this mean failover is working for you when g0/6 cable is plugged? Please plug back the cable and run the commands show failover and ...
- 3,754
3
votes
Cisco 3825 Router - Dual WAN Failover?
HSRP is for your LAN, not your WAN.
Normally it is very simple if you use static default routes.
On your WAN, you probably have a default route:
ip route 0.0.0.0 0.0.0.0 <next hop>
A static ...
- 98.8k
3
votes
Multiple ISPs failover configuration
Cisco has a good document that describes your exact scenario:
Configure the ASA for Redundant or Backup ISP Links
This document describes how to configure the Cisco ASA 5500 Series
Adaptive ...
- 67.1k
3
votes
Cisco failover interface in waiting
You are not using your ASA's in a failover configuration, so you should not configure them that way. Use the command
no failover
If you goal is to have one primary link and a backup link, oyu can ...
- 67.1k
3
votes
Accepted
Cisco failover interface in waiting
To solve this issue, you need at least a L2 switch in between.
If you would like to run dual ISPs, you can use another main/physical interface and terminate it on that L2 switch too, then separate L2 ...
- 3,754
3
votes
High availability LAN segment with Cisco ISR4451X and 2 x Netgear GS724 - Port-channel vs. BDI vs. BVI?
Configuring the router with a BVI interface seems to make the most sense. You can't use a port channel, and BDI is for IOS-XE routers. Make the router the root of the spanning tree.
- 67.1k
3
votes
Network routing/WAN failover
The issue is where/what you're tracking. You need to be able to continue to steer traffic over the down route in order to tell when it comes back up. Using PBR for traffic sourced from the router (ip ...
- 993
3
votes
ISP Failover On A Converged Network
Depending on how your network is set up, this is certainly possible.
You can configure the phones to pass VoIP on a dedicated, tagged VLAN and traffic from the internal switch untagged - this is what ...
- 82.7k
3
votes
Accepted
Virtual IP failover issue with vmware exsi ip based hashing
The ESXi's vSwitch doesn't care about IP addresses, just MACs. The "IP hash-based routing" is about L2 load balancing - which egress port is used - and has no relevance for IP routing.
You need to ...
- 82.7k
3
votes
How to know if ISP network have multiple routes
Personally, I do this type of research using a number of different publicly available "route servers" or "looking glasses." Simply do a web search for "public bgp looking glass" and you should find a ...
- 27.2k
3
votes
Accepted
Bonding and switching between 2 different Links/WANs/Interfaces
I don't want to use "both" interfaces/links/Wans at the same time,
instead I want to use one of them and in case it fails Bonding will
switch to the other source.
That is not bonding, where you ...
- 98.8k
3
votes
Accepted
eBGP failover without packet drops
Modify your Local Preference inbound on the eBGP relationship to the ISP on Core2 to be greater than 100. You will also need to add a route-map to AS-PATH prepend your prefix to the eBGP neighbour on ...
- 1,307
2
votes
Choosing between BGP (AS Number) and Dynamic DNS
when you speak about Dynamic DNS you actually speak about fail over on the level of services you need to be accessed in your site via internet (published mail server , web server or any other ...
- 3,444
2
votes
Preempt in ASA a/s fail over
According to Cisco, there are three ways for the formerly Active, now Standby, primary unit to again become Active:
Active unit failed (power or hardware)
Failover link failed at startup
Interface ...
- 98.8k
2
votes
Cisco ASA 5512 (OS 9.1(1)) HA failover issues
It turned out to be Port Security enabled on ISP access switches, which was blocking frames (following failover) for approx. 30 minutes. Thanks everyone and Ron Trunk especially
- 131
2
votes
MikroTik: bisschoff load balancing problem?
You can use the routerOS netwatch tool to monitor each ADSL's gateway. When netwatch detects a failure (=no more ping), you can execute a script to disable some rules, and another to re-enable them ...
- 256
2
votes
Lowest Possible Failover Latency
STP, including RSTP will fail over the slowest.
Routing protocols come in second place.
By far, the fastest failover is a port channel. As long as even one link in a port channel is up, the port ...
- 98.8k
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