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Questions tagged [redundancy]

For questions about network redundancy. For instance: you need to design a new network with high redundancy or you are troubleshooting an issue where it doesn't work.

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176 views

How does STP convergence work?

Consider the IEEE 802.1D (first revision) Spanning Tree Protocol. I have read a lot of articles and forum entries about STP convergence. Often I do find contradictions about the convergence mechanics. ...
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1answer
65 views

PVST + MST + RSTP network. Possible to make it work?

I have got a network (around 100 switches) which looks like this: Cisco 2960 - can do PVST, RSTP, MST MRV mr2228-s2c - can do STA, MSTP HP 1810 - can do RSTP, STP Two main Ciscos are linked with ...
4
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0answers
44 views

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:...
5
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1answer
64 views

Is it bad practice to use a Virtual Router for NTP-Clustering?

I'm trying to find information on whether it is possible to enable an NTP cluster containing multiple routers, that are configured with VRRP to share the same address. I am aware that with many ...
0
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1answer
79 views

How to connect high-availability routers to high-availability firewalls

I have two Juniper routers (a SRX340 and a SRX320), each with a leased line, on the same IP range. They are designed to be connected together on specific network ports so that the SRX320 takes over if ...
4
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2answers
71 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 ...
0
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2answers
59 views

Cisco 220 Switch fail over

we have a Cisco 220 Switch, how to fail over this switch, in other words how to have another switch that activates when the first dies? Thanks !!
1
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1answer
120 views

Pfsense CARP mutliwan

I'm currently trying to build a HA setup using Pfsense/CARP for the first time but i have a few questions about it. On the LAN side i have 3 VLAN's and they failover fine using CARP, the problem is ...
2
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2answers
175 views

redundant vpn to remote location with redundant links

I have this situation: Remote location with 6 devices collecting data and each connected to two VPN routers. Bonding is set up for those computers and data is sent to multicast address. Each VPN ...
1
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1answer
55 views

Can a router run GLBP for two subnets simultaneously on separate interfaces?

If I have a simple topology with three routers, R2 -- stub area 1 / ISP ----- R1 \ R3 -- stub area 2 and I want to alleviate both R2 and R3 from ...
3
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2answers
357 views

Connect two routers to a single uplink for full redundancy

I have a single uplink with my ISP at a data center. I have 2 routers (CISCO 3850). How do I connect these routers to that uplink WITHOUT a network switch? That switch will be a single point of ...
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1answer
280 views

How to implement Layer 3 (OSPF, IS-IS) link redundancy?

I think this kind of topic may be a course basic, but I'm still have a lot of technical doubts on how to implement redundant links on Layer 3, for example: -In order to use dual homing for a remote ...
0
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1answer
39 views

VDSL to LTE redundancy over 2 different CPEs suitable for small business

We would like to build up a full redundant internet access to our small business location. We have currently VDSL connection and would like to create a redundant connection over LTE as a backup. In ...
3
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2answers
176 views

OSPF Issue, redundancy between P2P (MPLS) and Firewall

I drew a diagram for the network to make it easy to understand my network issue. Site B,C and D communicate through MPLS and in case of failover they communicate through VPN tunnels. Site X ...
1
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1answer
45 views

Packet forwarding in HSR?

Does a node forward a packet further, even if the destination node is itself?
2
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1answer
1k views

ASA Redendent Failover and stateful link issue

We have ASA 5585-X and i create back-to-back (without intermediate switch/hub) two 1G cable between two ASA to create failover + stateful link using g0/6 and g0/7 interface. Interface config ! ...
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2answers
75 views

Network redundancy with low cost switches in a ring

I'm designing a network which is physically arranged like: |---------------------------[router]---------------------------| | | |--[s]--[s]...
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2answers
1k views

Fortigate VRRP or HA config

I have 2xFG 600D for redundancy setup, where to use VRRP and HA configuration? which one is optimal for Nat mode ?
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1answer
59 views

Running quagga on a redundant board? (how to force ospfd to not send HELLOs?)

In the image below i run quagga ospfd daemons as routers in picture. I want to add 1+1 redundancy to 172.16.1.0 network this way: if 172.16.1.1 became unavailable 172.16.1.128 changes its IP address ...
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1answer
63 views

How can use Load balancing?

if we do not configure HSRP or another protocol ,How data will flood if there is redundancy ? please help me I need some explain about load balancing
1
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1answer
290 views

Reduce ARP cache time-out?

I have active/passive servers cluster talking with another cluster located behind a Router, for some bug in the operating system in the first cluster it did not send GARP message after switch-over ...
2
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3answers
575 views

Fault tolerance with 3 routers in Packet Tracer

Given the following diagram, I've modified the static routing tables with an entry for each router of the other two, through the serial interface, and everything works fine. What should I change so ...
2
votes
1answer
38 views

Lab: I am running 15.1 on a catalyst and need to disable redundant supervisormp

I am trying to find a way to disable the redundant supervisor mode in my switch, as it is disabling another line card, so it can have enough power to spare for a redundant slot I wont use. I have ...
2
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1answer
111 views

link redundancy

In a scenario, there are three devices R_A, R_B, R_C and connected as shown in diagram, How can implement that Link 1 and Link 2 work in active and standby mode i.e. Link 2 will be active if Link 1 ...
2
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2answers
420 views

Multi-switch configuration with double uplink

We want to configure our new network with 2 switches, redundantly, so if one of the uplinks goes down, or one of the switches dies, the network keeps on going.. We have the following setup: (...
1
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2answers
544 views

Configuring redundancy Site to Site VPNs with different ISPs

I'm trying to configure two Site to Site VPNs from one Cisco ASA 5585x to two separate FWs with different ISPs. I found that multiple peer IP addresses can be configured under ASDM, Configuration > ...
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2answers
1k views

How fast can STP, RSTP, and MSTP find a new route?

If I have two switches connected redundantly and both are capable of using STP, RSTP, or MSTP, how quickly can an alternate route be detected and normal communication resume if the main route is ...
0
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1answer
96 views

BGP VPN created, how do I give access to internet

Head office is using real routers and switches and The redundancy btw HQ1 and HQ2 works. The rest of the network is inside GNS3, for now there is no connections between real routes and GNS3 (I will ...
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2answers
750 views

Adding a switch to provide redundancy

I inherited a network laid out (very broadly speaking) as follows: A number of access switches connect to 2 main switches. The Main Switch in the MDF (SW1) connects to the WAN router and is connected ...
1
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1answer
656 views

router on a stick and VRRP on the same router and full redundancy possible?

The routers on a stick are running VRRP on g0/0.10, g0/0.20 and g0/0.30. On switches, ports fa0/1-8 are on VLAN 10, fa0/23 and fa0/24 are configured as trunk port, with allowed VLANs 10, 20 and 30. ...
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2answers
581 views

Can I connect the two routers back to back to use HSRP? Please suggest

Current network is like - MSP network--> Cisco 4431--> ASA--> N7k--> LAN. I'm adding one more router and one more ASA in the network, Do I really need to add L2 switch to connect routers LAN side and ...
0
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1answer
649 views

Network redundancy design question with BGP

If you see following diagram we have two separate links (10G) coming from same ISP terminated on ASR 1006 router where we are planning to run BGP. From ASR 1006 two 10G fiber terminated to L3 switch. ...
1
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1answer
816 views

Load balancing between multiple layer 3 switches

I have two trunked L3 switches forming a network backbone. One is an old HP2848 and the other is a new Juniper EX3300. Currently only the EX3300 connects to our WAN Router and is trunked via 4 LACP ...
3
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2answers
71 views

Can links be aggregated in a way that provides packet level redundacy?

For the sake of the argument, let's talk TCP/IP, but if other technologies are more suitable, by all means, please say so! My understanding of classic link aggregation is a round-robin type send ...
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0answers
529 views

Cisco: Catalyst 4948E-E vs Nexus 3048 for Core Networking with iSCSI

I'm designing a network topology for our university department datacenter and looking for some help and advices with the core switch. Basically I'm targeting the Cisco Nexus 3048 with LAN Enterprise ...
1
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1answer
2k views

Stack switch with HSRP for Gateway redundancy

We have ws-c3850-48t two switch in stack. and from Internet Provide ISP we have two fiber drops coming for redundancy. I want to configure HSRP for failover but i believe stack switch work like single ...
4
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3answers
338 views

Redundancy in Internet core and edge networks - redundant devices and redundant links

Since inception, the resilience of the Internet has been based upon multiple paths from source to destination. At the granularity of the AS, this is generally implemented by linking to more than one ...
2
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1answer
674 views

Link aggregation / redundancy

We have two managed switches (Draytek VigorSwitch P2261) in our (small) office. They are connected to each other with two ports (LACP). We have four access points which provide plenty of coverage in ...
8
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2answers
95 views

Will STP lose data whilst switching from a failed link?

In a network with a dual-redundant link between two switches, will any data be lost during the switchover from an active link to the blocked link when the active link fails?
2
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2answers
2k views

Optimizing Router Topology (Redundancy)

In the previous question I have been trying to optimize switching topology. Now I would like to implement redundancy. And here are the problems I faced. Assuming the following topology As routers ...
2
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3answers
320 views

Satellite/3G redundancy

We have a site that currently has a satellite connection used by users, and a 3G connection used for a specific application. Connections are from different providers. Every connection has it's own ...
1
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1answer
61 views

i have two gateways for destination for single route

i have two gateways for single route Ex. destination 172.20.100.4 gateways 10.22.0.9 and 10.192.168.18 I want to add both routes in my route add if one is fail traffic goes automatically from ...
2
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1answer
2k views

Cisco HSRP with redundant links

I am not sure how to configure HSRP in my scenario: I have 2 distribution 2950 switches, each connected to two core 3560 switches. Distribution switches work in VTP transparent mode and (for now) ...
0
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0answers
1k views

Redundant ISP connections for failover on Fortinet Fortigate 1000D, do not need load balancing

I would like to use our second ISP connection as merely a backup connection to the WAN in case the ISP1 connection goes down. We do not need to load balance yet as we are not consuming enough of the ...
5
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3answers
2k views

Two ISP bgp topology?

We use palo-alto firewall as an internet gateway. We have 16 static ip-addresses. One is used for outbound traffic (users browse internet) . The rest is used for inbound traffic (mail server, ...
0
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1answer
78 views

Question about graceful restart

i do some research on graceful restart for OSPF, BGP, LDP. After i read those RFCs for these protocols, i have a question want to ask that if a router really goes down not restart (i.e. power off...), ...
3
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2answers
3k views

Master stack switch turn off

I have two switches in a stack. One is master and the other is a slave. If I turn off the slave, the master will work with no problem. My questions: if I turn off the master, will the slave still ...
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1answer
215 views

Do I have to configure a level 2 LACP capable switch for it to work properly on a network with LACP redundant switches

Ok this question is related to Can I use an unmanaged switch as a substitute for redundant, stacked switches when using a single network card? I have network with two stacked Cisco 2960 switches ...
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1answer
496 views

Can I use an unmanaged switch as a substitute for redundant, stacked switches when using a single network card?

I am building a network with stacked switches for redundancy. The problem I have is that some of the machines connected to the network will only have one available network card. This card is not a ...
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2answers
809 views

How to properly configure STP in this simple setup?

In the network below, I have a simple setup of two hosts (R1 and R2). They both are connected to a L2 access switch. Both the L2 access switches are connected on two interfaces to the L3 distribution ...