public static void addHttp2DefaultConfig(ChannelConfig config, String listenAddressName) {
        config.add(new ChannelConfigValue<>(
                CommonChannelConfigKeys.maxConcurrentStreams,
                chooseIntChannelProperty(
                        listenAddressName,
                        "http2.max.concurrent.streams",
                        CommonChannelConfigKeys.maxConcurrentStreams.defaultValue())));
        config.add(new ChannelConfigValue<>(
                CommonChannelConfigKeys.initialWindowSize,
                chooseIntChannelProperty(
                        listenAddressName,
                        "http2.initialwindowsize",
                        CommonChannelConfigKeys.initialWindowSize.defaultValue())));
        config.add(new ChannelConfigValue<>(
                CommonChannelConfigKeys.maxHttp2HeaderTableSize,
                chooseIntChannelProperty(listenAddressName, "http2.maxheadertablesize", 65536)));
        config.add(new ChannelConfigValue<>(
                CommonChannelConfigKeys.maxHttp2HeaderListSize,
                chooseIntChannelProperty(listenAddressName, "http2.maxheaderlistsize", 32768)));

        // Override this to a lower value, as we'll be using ELB TCP listeners for h2, and therefore the connection
        // is direct from each device rather than shared in an ELB pool.
        config.add(new ChannelConfigValue<>(
                CommonChannelConfigKeys.maxRequestsPerConnection,
                chooseIntChannelProperty(listenAddressName, "connection.max.requests", 4000)));

        config.add(new ChannelConfigValue<>(
                CommonChannelConfigKeys.http2AllowGracefulDelayed,
                chooseBooleanChannelProperty(listenAddressName, "connection.close.graceful.delayed.allow", true)));
        config.add(new ChannelConfigValue<>(
                CommonChannelConfigKeys.http2SwallowUnknownExceptionsOnConnClose,
                chooseBooleanChannelProperty(listenAddressName, "connection.close.swallow.unknown.exceptions", false)));
    }
First looks for a property specific to the named listen address of the form -
"server.${addrName}.${propertySuffix}". If none found, then looks for a server-wide property of the form -
"server.${propertySuffix}".  If that is also not found, then returns the specified default value.
zuul-core/src/main/java/com/netflix/zuul/netty/server/BaseServerStartup.java