Enterprises keep moving workloads to AWS, Azure, and Google Cloud. And with every migration, Network Address Translation (NAT) sits there \u2014 invisible, doing its job between your applications and the public internet. Cloud NAT services solve an immediate problem, sure: they let private instances reach outbound destinations without public IPs. But they introduce trade-offs in Cloud NAT performance<\/strong> that many teams only discover the hard way. A user complains about latency. Connections drop. Emails bounce. Nobody knows why.<\/p>\n This article looks at how shared NAT gateways affect throughput, latency, and connection reliability \u2014 and why allocating dedicated IPv4 addresses is often the smarter long-term bet.<\/p>\n Cloud NAT gateways (AWS NAT Gateway, Azure NAT Gateway, Google Cloud NAT) perform source NAT: they translate private RFC 1918 addresses to a shared public IP and keep a translation table of active flows. Every outbound connection eats a TCP\/UDP port on the gateway. The service is managed, highly available \u2014 fine. But the architecture creates constraints that don’t go away:<\/p>\n Benchmarks consistently show that NAT-induced degradation depends heavily on the workload. Some typical patterns:<\/p>\n A practical rule of thumb: AWS NAT Gateway processes up to 55,000 packets per second and can scale to 100 Gbps. Impressive on paper. But that capacity is shared. A single misbehaving workload \u2014 a runaway retry loop, for example \u2014 can consume disproportionate gateway resources and drag down neighboring applications with it.<\/p>\n Port exhaustion is the most common Cloud NAT failure mode, and it’s a quiet one. When a gateway runs out of available translation ports toward a specific destination, new connections get dropped \u2014 sometimes silently, sometimes with an explicit error. Google Cloud NAT, for instance, allocates a minimum of 64 ports per VM per destination. Teams running thousands of short-lived connections must manually raise this number or live with intermittent failures.<\/p>\n Even when raw performance is acceptable, shared egress IPs carry reputational risk. If another tenant on the same NAT pool sends spam or scrapes aggressively, blocklists (Spamhaus, SORBS) may flag the shared address \u2014 your address, effectively. What happens then?<\/p>\n For e-commerce, SaaS, and financial services, a single blacklisted egress IP can cost more in lost transactions than a full year of dedicated IP costs.<\/p>\n Assigning dedicated IPv4 addresses \u2014 per workload, per tenant, or per region \u2014 eliminates most NAT-related performance and reputation issues. What do you actually get?<\/p>\n Some managed NAT solutions let you attach dedicated IPs to the gateway, which does solve the reputation problem. But you still pay hourly NAT processing fees, and the translation overhead stays. True dedicated IPv4 allocations remove the middleman entirely.<\/p>\n Does Cloud NAT really add noticeable latency?<\/strong> For most web traffic, the added sub-millisecond overhead is negligible. For high-frequency trading, real-time bidding, or high-packet-rate workloads, it compounds with variance under load and becomes measurable. So: depends.<\/p>\n Can I use dedicated IPs with managed NAT?<\/strong> Yes \u2014 all major clouds let you attach your own IPs to NAT gateways or use BYOIP with dedicated egress. This improves reputation but retains per-GB NAT costs and translation overhead.<\/p>\n How much does a dedicated IPv4 address cost?<\/strong> Market prices have ranged between $30\u2013$60 per address in recent years, depending on block size and RIR. For steady outbound-heavy workloads, a one-time purchase often beats cumulative NAT processing fees.<\/p>\n What should I verify before buying IPv4 space?<\/strong> Confirm clean blocklist history, legitimate WHOIS records, RIR transfer readiness, and no route hijack history \u2014 services like IP4 Market handle this verification as part of the transaction.<\/p>\n<\/div>\n Cloud NAT is convenient. But convenience has a price: shared ports, shared reputation, shared fate. For latency-sensitive, connection-heavy, or reputation-critical applications, dedicated IPv4 addresses deliver predictable Cloud NAT performance<\/strong> improvements \u2014 or remove the NAT layer altogether. And as the IPv4 market tightens, securing clean, dedicated address space through a verified marketplace like IP4 Market stops being a nice-to-have. It becomes an infrastructure decision that pays for itself in reliability, deliverability, and, honestly, peace of mind.<\/p>\n\n
How Cloud NAT Works \u2014 and Where the Bottlenecks Hide<\/h2>\n
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Measurable Performance Impact on Real Applications<\/h2>\n
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The Port Exhaustion Problem Explained<\/h2>\n
Shared IPs, Reputation, and Deliverability<\/h2>\n
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Why Dedicated IPv4 Addresses Win<\/h2>\n
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Side-by-Side Comparison<\/h2>\n
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\n \nCriteria<\/th>\n Shared Cloud NAT<\/th>\n Dedicated IPv4<\/th>\n<\/tr>\n<\/thead>\n \n Latency overhead<\/td>\n Translation hop, variable under load<\/td>\n Minimal, direct path<\/td>\n<\/tr>\n \n Port availability<\/td>\n Shared, exhaustion risk<\/td>\n Full \/64K per IP per destination<\/td>\n<\/tr>\n \n IP reputation<\/td>\n Shared with unknown tenants<\/td>\n Fully controlled<\/td>\n<\/tr>\n \n Ongoing cost<\/td>\n Hourly fees + per-GB processing<\/td>\n One-time purchase + hosting<\/td>\n<\/tr>\n \n Compliance\/whitelisting<\/td>\n Difficult, unstable<\/td>\n Straightforward<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n Practical Tips for Moving to Dedicated IPv4<\/h2>\n
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Frequently Asked Questions<\/h2>\n
Conclusion: Control Your Egress, Control Your Performance<\/h2>\n