The topology of the testing is shown balancing capability. It will ignore all other in Figure 4. The reason viewed as useless packets and dropped for choosing this way to collect data is that all the without any error. Because the original routers traffic can be monitored at the same time and VRRP state diagram does not support the traffic changes can be easily shown. Load Balancing Capability Test router is down and then transit itself to the Master router. First we generate a stable traffic load for Routers 13, 14 and Evaluation traffic.
Then we disconnect Router 15 and 14 sequentially until only Router 13 is alive and acts as The major benefits from EVRRP are the very low the master router to route all traffic. The master router overhead in CPU consumption of its load-balancing transfers traffic from Router 15 to Router Since the and fail-over capabilities and the backward maximum physical bandwidth is Mbps for each compatibility to the VRRP standard.
Besides, the traffic timeout, and packets forwarding and rebalancing can be evenly distributed to every router after a new between the backup routers and the master router.
There are clients and 12 servers using HTTP as testing tool. Figure 5. The standard VRRPd. After the traffic becomes stable, following figures show the traffic how to distribute Router 15 shutdown to promote Router 14 to the among the routers.
Figure 8 shows the traffic monitored by client side. Figure 6. The While the Router 15 is working, it can redirect part new join router can only share the master router traffic. As a result, the master router Router 15 will not redirect any traffic to Router After Router 15 is failed, Router 14 takes over as the master router. Therefore, all traffic is taken over by to router 14 as in the VRRP standard. Figure 7. So beside the data traffic of Router 14 to Routers 14 and Previously traffic, ICMP redirection packets also consume part of dispatched traffic through Router 13 must wait until an the total available bandwidth.
We use the 3-router test ICMP redirection timeout to redistribute the traffic 1 master router, 2 backup routers to analyze the evenly. ICMP traffic load. In the tests, we reduce the ICMP redirection timeout from to 60 seconds on client 7. In these tests, ICMP packets only represent 0. Since the first two cases do not only 0. We only monitor the master router for the support load-balancing, to be fair we generate only number of total ICMP packets since the master router Mbps traffic for testing.
All the data are the is the only source which generates ICMP packets. Most of the CPU traffic for heartbeats. Each backup router generates load is generated by System process. Figure 12 shows the router and the master router, we simplify the test to condition of the backup router fails. It shows a large timeout gap master and the backup router.
Host A sends test data because the master router will notice the backup router FTPput packets to host B through the master router has failed after not receiving heartbeat from the backup or the backup router during a period of one minute.
Our testing and measurement software is the popular The traffic drop in the figure on the left arises from the NetIQ Chariot [10]. During each testing period, we redirection of data packets from the backup to the unplug the Ethernet connection of the master or master, while the gap on the right in the future is due backup routers at 10 second to simulate router failure to the rebalancing of the data packets from the master and restore the connection at 30 second to simulate to the backup.
Figure 9 shows the VRRP failover timeout which is about 5 seconds under test. Figure Backup Router Traffic while it Changes Figure 9. Its simplicity and short fail-over time outperform other dynamic routing protocols such as RIP and deploying the protocol does not require any modification of network settings for hosts in LAN. Traffic Redirection and Balancing believe that EVRRP protocol will be important for small to medium enterprise or campus networks as an The EVRRP will redirect some traffic to idle economical solution to achieve high dependability in backup routers for load balancing.
Sample Configuration 1 The following figure shows a simple network with two VRRP routers implementing one virtual router. Note that this example is provided to help understand the protocol, but is not expected to occur in actual practice.
A virtual router is then defined by associating a unique identifier the virtual router ID with the address owned by a router. Finally, the VRRP protocol manages virtual router fail over to a backup router. In order to backup IP B, a second virtual router must be configured. This is shown in the next section. Sample Configuration 2 The following figure shows a configuration with two virtual routers with the hosts spitting their traffic between them.
This example is expected to be very common in actual practice. This scenario demonstrates a deployment providing load splitting when both routers are available while providing full redundancy for robustness. IP Field Descriptions 5. Source Address The primary IP address of the interface the packet is being sent from. This document defines version 2. Configurable item in the range decimal.
There is no default. Higher values equal higher priority. This field is an 8 bit unsigned integer field. The default priority value for VRRP routers backing up a virtual router is decimal.
The priority value zero 0 has special meaning indicating that the current Master has stopped participating in VRRP. This is used to trigger Backup routers to quickly transition to Master without having to wait for the current Master to timeout. Authentication Type The authentication type field identifies the authentication method being utilized. Authentication type is unique on a Virtual Router basis.
The authentication type field is an 8 bit unsigned integer. A packet with unknown authentication type or that does not match the locally configured authentication method MUST be discarded. These were removed in this specification because operational experience showed that they did not provide any real security and would only cause multiple masters to be created. The authentication methods currently defined are: 0 - No Authentication 1 - Reserved 2 - Reserved 5. The contents of the Authentication Data field should be set to zero on transmission and ignored on reception.
Authentication Type 1 - Reserved This authentication type is reserved to maintain backwards compatibility with RFC Authentication Type 2 - Reserved This authentication type is reserved to maintain backwards compatibility with RFC The default is 1 second.
This field is used for troubleshooting misconfigured routers. The checksum is the bit one's complement of the one's complement sum of the entire VRRP message starting with the version field. For computing the checksum, the checksum field is set to zero. The number of addresses included is specified in the "Count IP Addrs" field. These fields are used for troubleshooting misconfigured routers.
Authentication Data The authentication string is currently only used to maintain backwards compatibility with RFC Protocol State Machine 6. The value of decimal is reserved for the router that owns the IP addresses associated with the virtual router.
The range decimal is available for VRRP routers backing up the virtual router. The default value is decimal. Configured item. No default. Default is 1 second. Values are True to allow preemption and False to prohibit preemption. Default is True. Note: Exception is that the router that owns the IP address es associated with the virtual router always preempts independent of the setting of this flag.
Values are defined in section 5. A VRRP router implements an instance of the state machine for each virtual router election it is participating in. Initialize The purpose of this state is to wait for a Startup event. If the packet was not generated by the address owner Priority does not equal decimal , the receiver MUST drop the packet, otherwise continue processing. The next two octets indicate the address block assigned to the VRRP protocol.
This mapping provides for up to VRRP routers on a network. Operational Issues 8. This allows VRRP to be used in environments where the topology is not symmetric. The IP source address of an ICMP redirect should be the address the end host used when making its next hop routing decision.
If a VRRP router is acting as Master for virtual router s containing addresses it does not own, then it must determine which virtual router the packet was sent to when selecting the redirect source address.
One method to deduce the virtual router used is to examine the destination MAC address in the packet that triggered the redirect. It may be useful to disable Redirects for specific cases where VRRP is being used to load share traffic between a number of routers in a symmetric topology. This allows the client to always use the same MAC address regardless of the current Master router.
Forwarding these packets would result in unnecessary traffic. Also in the case of LANs that receive packets they transmit e. Under some conditions, such as router isolations, ring failures, protocol transitions, etc. These include: - In order to switch to a new master located on a different bridge token ring segment from the previous master when using source route bridges, a mechanism is required to update cached source route information. This is because the destination device will assume it is connected a single source at all times, even across reconnections.
The VRRP functionality can be extended with scripts. VyOS supports two kinds of scripts: health check scripts and transition scripts. Health check scripts execute custom checks in addition to the master router reachability. Transition scripts are executed when VRRP state changes from master to backup or fault and vice versa, and can be used to enable or disable certain services, for example.
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