We all know the obvious truth that more/multiple uplinks will provide better long term availability of any environment. However, whether more/multiple uplinks is the "better" choice for your organization is not necessarily quite as obvious. A more detailed look into the pros and cons of single vs multiple uplinks is presented below to determine what truly may be the better option for your organization.
Single uplink:
Pros:
- Easy to configure
- Minimal “human error” failures related to loops in the network topology
- Inexpensive
Cons:
- Subject to periodic downtimes associated with scheduled maintenance (always between 12-6AM on Saturdays) by Netriplex in addition to any downtimes associated with scheduled maintenance by your business.
- Higher risk of unplanned downtime (customer switch can fail/lockup, OR cabling for the single uplink can fail, OR Netriplex switch can fail/lockup). Any SINGLE failure of ANY device in the path will cause an outage.
- Connection to only 1 Netriplex switch
- Covered by a 99.9% network uplink SLA as it is known that downtimes are more likely do to the single path nature of the configuration.
Summary:
If your business can tolerate scheduled downtimes of 1-2 hours each, 2-3 times per year during overnight hours (local time to the datacenter), and the potential for an unplanned outage due to equipment failure every 18-24 months (statistical average), the simplicity of a single uplink and the ease of configuration usually makes it a better choice.
Redundant Uplinks:
Pros (if the redundant uplinks are properly configured for HA):
- Customer environment will remain available during periods of scheduled maintenance
- Unplanned downtime much less likely (multiple failures would need to occur at the same time to bring down the environment, at least 1 device on each path must be in a failed state)
- Each uplink will be connected to different Netriplex switchgear to protect against equipment failure
- Covered by a 100% network uptime SLA
Cons:
- To properly configure and fully take advantage of the high availability of multiple uplinks, the customer environment would need multiple network devices configured in an architecture for high availability. This includes multiple firewalls/routers/L3 switches configured as a failover pair with each device having a separate diverse path onto our network.
- Because of multiple paths existing, greater potential for human error related to configurations causing a routing loop
- Additional cost associated with additional connectivity. Prices varies depending on the type and speed of the connection.
Summary:
If the “opportunity cost” to your business related to periodic outages due to scheduled maintenance windows as well as the higher probability of unplanned downtimes is greater than the cost to deploy and maintain a redundant, highly available network architecture, redundant uplinks and a HA network architecture may be the better choice for your organization. We typically caution against taking multiple uplinks if you intend to terminate both uplinks into the same switch/router/firewall as the added benefit is relatively small and it introduces a higher chance of a “loop” failure than a properly deployed HA network architecture.